Fixed: - leak on engine._releaseTexture()
- size change on post FX (optim possible if we get a global "size changed event" to avoid calculate and compare render width / render height at each frame)

optim : -disable depth buffer test & write on post fx
- avoid creating depthbuffer for the post process render targets if they are not the first on the pipeline

added : -fxaa PostProcess -> todo : make some settings available to tweak the "smoothness" effect depending on the scene
-toggle black and white and fxaa buttons on camera settings (samples)
-jscompaktor.bat to make it easier to build babylon for new contributors

known issues : -if there are multiple post-processes active on the same camera and the user disable the 1st one in the pipeline, the rendering target of the new "first effect in pipeline" has no depth buffer (and so the rendering is broken until the user resize the window).
Added: - option to specify the sampling mode of a renderTargetTexture
- option to override the sampling mode used by a PostProcess effect (defaulted to NEAREST as it is faster, usually perfectly suited for full screen post process effects and consumes a bit less fillrate)
- option to add FSAA 4X antialiasing (uses passPostProcess with ratio x2 and bilinear sampling)
fixed: - bug when removing the first post process of a post processing chain
Merge pull request #95 from simonferquel/master

FXAA support