CCRenderTexture's -newCGImage method read pixels outside the render queue.
This lead to wrong previews in SpriteBuilder. After correcting this the image was flipped, fixed that as well.
Methods added to allow saving of image to arbitrary file paths.
Remove CCEffectBrightnessAndContrast

It's no longer needed now that we have stacking and CCEffectBrightness and CCEffectContrast.
Get stitched effects working again

- Do not return the default CCEffect uniforms from CCEffectStack's extraFragment / VertexData methods.
- Restore the renderPassUpdate default block for super-simple effects like CCEffectTexture and CCEffectColorPulse.
  This allows these effects to not implement their own renderPassUpdate methods and still have things work.
- Re-enable setupEffectNodeTest in the effects test.
Set the position+color+texture shader in CCEffectNode's post-rendering composite phase

The original implementation of post-render composite phase didn't set the shader which meant
it was left as whatever the last effect's last render pass had set it to. This hadn't caused any visible
problems yet but it would have eventually and it also meant we were running a more expensive
shader than we needed to be.
Fixed anchor point bugs for CCRenderTexture and CCEffectNode, correctly implemented setContentSize so that CCRenderTexture and CCEffectNode behave like any CCNode. This should help fix weird collision check issues that I was running into when making a demo.
Fixed anchoring bugs in CCRenderTexture, now CCRenderTexture supports setContentSize and will also behave like a CCNode in regards to anchorPoints.
Merge branch 'develop' of github.com:osinoleg/cocos2d-iphone into develop

Conflicts:
	cocos2d/CCEffectNode.m
Merge remote-tracking branch 'upstream/develop' into develop
Merge pull request #757 from osinoleg/develop

CCEffects - content size fixes and clean up
Merge branch 'bugfix/3.1/sb#416_previews_screwed_up' of git://github.com/NickyWeber/cocos2d-iphone into develop
Merge pull request #752 from NickyWeber/feature/3.1/CCRenderTexture_more_flexible_saveToFile

Methods added to allow saving of image to arbitrary file paths.