README: expand with "Running Geth" section

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@ -54,6 +54,197 @@ The go-ethereum project comes with several wrappers/executables found in the `cm
 | `gethrpctest` | Developer utility tool to support our [ethereum/rpc-test](https://github.com/ethereum/rpc-tests) test suite which validates baseline conformity to the [Ethereum JSON RPC](https://github.com/ethereum/wiki/wiki/JSON-RPC) specs. Please see the [test suite's readme](https://github.com/ethereum/rpc-tests/blob/master/README.md) for details. |
 | `rlpdump` | Developer utility tool to convert binary RLP ([Recursive Length Prefix](https://github.com/ethereum/wiki/wiki/RLP)) dumps (data encoding used by the Ethereum protocol both network as well as consensus wise) to user friendlier hierarchical representation (e.g. `rlpdump --hex CE0183FFFFFFC4C304050583616263`). |
 ## Running geth
 Going through all the possible command line flags is out of scope here (please consult our
 [CLI Wiki page](https://github.com/ethereum/go-ethereum/wiki/Command-Line-Options)), but we've
 enumerated a few common parameter combos to get you up to speed quickly on how you can run your
 own Geth instance.
 ### Full node on the main Ethereum network
 By far the most common scenario is people wanting to simply interact with the Ethereum network:
 create accounts; transfer funds; deploy and interact with contracts. For this particular use-case
 the user doesn't care about years-old historical data, so we can fast-sync quickly to the current
 state of the network. To do so:
 ```
 $ geth --fast --cache=512 console
 ```
 This command will:
 * Start geth in fast sync mode (`--fast`), causing it to download more data in exchange for avoiding
   processing the entire history of the Ethereum network, which is very CPU intensive.
 * Bump the memory allowance of the database to 512MB (`--cache=512`), which can help significantly in
   sync times especially for HDD users. This flag is optional and you can set it as high or as low as
   you'd like, though we'd recommend the 512MB - 2GB range.
 * Start up Geth's built-in interactive [JavaScript console](https://github.com/ethereum/go-ethereum/wiki/JavaScript-Console),
   (via the trailing `console` subcommand) through which you can invoke all official [`web3` methods](https://github.com/ethereum/wiki/wiki/JavaScript-API)
   as well as Geth's own [management APIs](https://github.com/ethereum/go-ethereum/wiki/Management-APIs).
   This too is optional and if you leave it out you can always attach to an already running Geth instance
   with `geth --attach`.
 ### Full node on the Ethereum test network
 Transitioning towards developers, if you'd like to play around with creating Ethereum contracts, you
 almost certainly would like to do that without any real money involved until you get the hang of the
 entire system. In other words, instead of attaching to the main network, you want to join the **test**
 network with your node, which is fully equivalent to the main network, but with play-Ether only.
 ```
 $ geth --testnet --fast --cache=512 console
 ```
 The `--fast`, `--cache` flags and `console` subcommand have the exact same meaning as above and they
 are equially useful on the testnet too. Please see above for their explanations if you've skipped to
 here.
 Specifying the `--testnet` flag however will reconfigure your Geth instance a bit:
 * Instead of using the default data directory (`~/.ethereum` on Linux for example), Geth will nest
   itself one level deeper into a `testnet` subfolder (`~/.ethereum/testnet` on Linux).
 * Instead of connecting the main Ethereum network, the client will connect to the test network,
   which uses different P2P bootnodes, different network IDs and genesis states.
 *Note: Although there are some internal protective measures to prevent transactions from crossing
 over between the main network and test network (different starting nonces), you should make sure to
 always use separate accounts for play-money and real-money. Unless you manually move accounts, Geth
 will by default correctly separate the two networks and will not make any accounts available between
 them.*
 ### Programatically interfacing Geth nodes
 As a developer, sooner rather than later you'll want to start interacting with Geth and the Ethereum
 network via your own programs and not manually through the console. To aid this, Geth has built in
 support for a JSON-RPC based APIs ([standard APIs](https://github.com/ethereum/wiki/wiki/JSON-RPC) and
 [Geth specific APIs](https://github.com/ethereum/go-ethereum/wiki/Management-APIs)). These can be
 exposed via HTTP, WebSockets and IPC (unix sockets on unix based platroms, and named pipes on Windows).
 The IPC interface is enabled by default and exposes all the APIs supported by Geth, whereas the HTTP
 and WS interfaces need to manually be enabled and only expose a subset of APIs due to security reasons.
 These can be turned on/off and configured as you'd expect.
 HTTP based JSON-RPC API options:
  * `--rpc` Enable the HTTP-RPC server
  * `--rpcaddr` HTTP-RPC server listening interface (default: "localhost")
  * `--rpcport` HTTP-RPC server listening port (default: 8545)
  * `--rpcapi` API's offered over the HTTP-RPC interface (default: "eth,net,web3")
  * `--rpccorsdomain` Comma separated list of domains from which to accept cross origin requests (browser enforced)
  * `--ws` Enable the WS-RPC server
  * `--wsaddr` WS-RPC server listening interface (default: "localhost")
  * `--wsport` WS-RPC server listening port (default: 8546)
  * `--wsapi` API's offered over the WS-RPC interface (default: "eth,net,web3")
  * `--wsorigins` Origins from which to accept websockets requests
  * `--ipcdisable` Disable the IPC-RPC server
  * `--ipcapi` API's offered over the IPC-RPC interface (default: "admin,debug,eth,miner,net,personal,shh,txpool,web3")
  * `--ipcpath` Filename for IPC socket/pipe within the datadir (explicit paths escape it)
 You'll need to use your own programming environments' capabilities (libraries, tools, etc) to connect
 via HTTP, WS or IPC to a Geth node configured with the above flags and you'll need to speak [JSON-RPC](http://www.jsonrpc.org/specification)
 on all transports. You can reuse the same connection for multiple requests!
 **Note: Please understand the security implications of opening up an HTTP/WS based transport before
 doing so! Hackers on the internet are actively trying to subvert Ethereum nodes with exposed APIs!
 Further, all browser tabs can access locally running webservers, so malicious webpages could try to
 subvert locally available APIs!**
 ### Operating a private network
 Maintaining your own private network is more involved as a lot of configurations taken for granted in
 the official networks need to be manually set up.
 #### Defining the private genesis state
 First, you'll need to create the genesis state of your networks, which all nodes need to be aware of
 and agree upon. This consists of a small JSON file (e.g. call it `genesis.json`):
 ```json
 {
  "alloc"      : {},
  "coinbase"   : "0x0000000000000000000000000000000000000000",
  "difficulty" : "0x20000",
  "extraData"  : "",
  "gasLimit"   : "0x2fefd8",
  "nonce"      : "0x0000000000000042",
  "mixhash"    : "0x0000000000000000000000000000000000000000000000000000000000000000",
  "parentHash" : "0x0000000000000000000000000000000000000000000000000000000000000000",
  "timestamp"  : "0x00"
 }
 ```
 The above fields should be fine for most purposes, although we'd recommend changing the `nonce` to
 some random value so you prevent unknown remote nodes from being able to connect to you. If you'd
 like to pre-fund some accounts for easier testing, you can populate the `alloc` field with account
 configs:
 ```json
 "alloc": {
  "0x0000000000000000000000000000000000000001": {"balance": "111111111"},
  "0x0000000000000000000000000000000000000002": {"balance": "222222222"}
 }
 ```
 With the genesis state defined in the above JSON file, you'll need to initialize **every** Geth node
 with it prior to starting it up to ensure all blockchain parameters are correctly set:
 ```
 $ geth init path/to/genesis.json
 ```
 #### Creating the rendezvous point
 With all nodes that you want to run initialized to the desired genesis state, you'll need to start a
 bootstrap node that others can use to find each other in your network and/or over the internet. The
 clean way is to configure and run a dedicated bootnode:
 ```
 $ bootnode --genkey=boot.key
 $ bootnode --nodekey=boot.key
 ```
 With the bootnode online, it will display an [`enode` URL](https://github.com/ethereum/wiki/wiki/enode-url-format)
 that other nodes can use to connect to it and exchange peer information. Make sure to replace the
 displayed IP address information (most probably `[::]`) with your externally accessible IP to get the
 actual `enode` URL.
 *Note: You could also use a full fledged Geth node as a bootnode, but it's the less recommended way.*
 #### Starting up your member nodes
 With the bootnode operational and externally reachable (you can try `telnet <ip> <port>` to ensure
 it's indeed reachable), start every subsequent Geth node pointed to the bootnode for peer discovery
 via the `--bootnodes` flag. It will probably also be desirable to keep the data directory of your
 private network separated, so do also specify a custom `--datadir` flag.
 ```
 $ geth --datadir=path/to/custom/data/folder --bootnodes=<bootnode-enode-url-from-above>
 ```
 *Note: Since your network will be completely cut off from the main and test networks, you'll also
 need to configure a miner to process transactions and create new blocks for you.*
 #### Running a private miner
 Mining on the public Ethereum network is a complex task as it's only feasible using GPUs, requiring
 an OpenCL or CUDA enabled `ethminer` instance. For information on such a setup, please consult the
 [EtherMining subreddit](https://www.reddit.com/r/EtherMining/) and the [Genoil miner](https://github.com/Genoil/cpp-ethereum)
 repository.
 In a private network setting however, a single CPU miner instance is more than enough for practical
 purposes as it can produce a stable stream of blocks at the correct intervals without needing heavy
 resources (consider running on a single thread, no need for multiple ones either). To start a Geth
 instance for mining, run it with all your usual flags, extended by:
 ```
 $ geth <usual-flags> --mine --minerthreads=1 --etherbase=0x0000000000000000000000000000000000000000
 ```
 Which will start mining bocks and transactions on a single CPU thread, crediting all proceedings to
 the account specified by `--etherbase`. You can further tune the mining by changing the default gas
 limit blocks converge to (`--targetgaslimit`) and the price transactions are accepted at (`--gasprice`).
 ## Contribution
 Thank you for considering to help out with the source code! We welcome contributions from