Review for the gsoc UI cleanup for the BGE.
Surviving commits are:
- Game Engine UI cleanup: removing Scene/Active Clip
- Game Engine UI cleanup: Adding missing 'not available' labels in empty panels
The rest was reverted for being subjective and polluting the UI code with an if for every button:
http://wiki.blender.org/index.php/User:Brita/GSoC_BGE_cleanup_and_support/reports/final#UI_Review