Refactor.
First stage towards improving the loading/initialising of the scripting environment.

The old way is to just load script strings, but this is less efficient than it should be, so it is being changed to use the proper C API.
Scripting: Move Display to GTEngine.Display.
More script cleanup/refactoring.
Cleanup.
Stop using global variables created by GTGUI in preparation for changes about to be made there.
Fix GCC warnings.
Update CodeBlocks project.
Fix GCC warning.
Fix a bug where a null GUI element was being used in the scene editor.
Add the SynchronizedRCQueue class and use it with the resource RC queues in the OpenGL 2.0 renderer.
Small improvement to the GUI renderer.

Part of this change moves the initialization routine to a later stage after the libraries are initialised. This is required so that the GUI renderer can access a shader.
Fixes to RCQueue and SynchronizedRCQueue.
Memory leak fixes.