Require authenticated user for editor access

Previously, anyone could access the editor even if they weren't logged
in. They couldn't do much in that case (publishing would fail), but it
could potentially cause some confusion.

Now, users will be sent to the login page, and then redirected back to
the editor once successfully logged in.

routes.go

@@ -169,9 +169,9 @@ func InitRoutes(apper Apper, r *mux.Router) *mux.Router {
 	draftEditPrefix := ""
 	if apper.App().cfg.App.SingleUser {
 		draftEditPrefix = "/d"
-		write.HandleFunc("/me/new", handler.Web(handleViewPad, UserLevelOptional)).Methods("GET")
+		write.HandleFunc("/me/new", handler.Web(handleViewPad, UserLevelUser)).Methods("GET")
 	} else {
-		write.HandleFunc("/new", handler.Web(handleViewPad, UserLevelOptional)).Methods("GET")
+		write.HandleFunc("/new", handler.Web(handleViewPad, UserLevelUser)).Methods("GET")
 	}
 
 	// All the existing stuff