Factored the build RPC generator setup in its own function.
Converted the HostState enum to a C++11 enum class.
Removed mixed tabs/spaces in Editor/API.h.
Added RPC generation using the new function to the Editor.Shared build.
Changed the namespace from Flood.Editor.GUI.Controls to Flood.Editor.Controls.
Use an object initializer in DocumentTab.cs.
Added new premake4.exe build with the new "startproject" command.

Since our patch was accepted upstream we do not need our own version of it anymore.
Added a pane abstract class and changed the ProjectPane to use it.
Link the managed engine and server projects to Editor.Client.
Updated the initialization of the editor.