Merge pull request #33 from javierpuntonet/develop

Update GPUImageToneCurveFilter.java
Merge pull request #35 from javierpuntonet/develop

TwoPassFilter, Crosshatch, GaussianBlur
Add samples for GaussianBlur and Crosshatch
Fix formatting
Add some documentation
Merge pull request #5 from CyberAgent/develop

Develop