add single execution context

src/app/debugger/debugger.js

@@ -3,7 +3,7 @@
 var remixDebugger = require('remix-debugger')
 var remixLib = require('remix-lib')
 var remixCore = require('remix-core')
-var executionContext = remixLib.execution.executionContext
+var executionContext = require('../execution/execution-context')
 
 /**
  * Manage remix and source highlighting

src/app/execution/execution-context.js

@@ -0,0 +1,4 @@
+var remixLib = require('remix-lib')
+var executionContext = remixLib.execution.executionContext
+
+module.exports = executionContext

src/app/execution/txLogger.js

@@ -10,7 +10,7 @@ var styles = styleGuide.chooser()
 
 var EventManager = remixLib.EventManager
 var helper = require('../../lib/helper')
-var executionContext = remixLib.execution.executionContext
+var executionContext = require('./execution-context')
 var modalDialog = require('../ui/modal-dialog-custom')
 var typeConversion = require('../../lib/typeConversion')