Cleans a bit performance main file
Cleans and updates RenderBin/RenderLeaf/Program for example EarlyZ

- Adds new ColorMask StateAttribute ( void to write in the framebuffer )
- Moves renderin code from RenderBin to RenderLeaf
- Cleans up the state.applyStateSet and removed programs stack in State
Merge pull request #203 from cedricpinson/example/earlyz

Example/earlyz