Blending modes
GPUImageTwoInputFilter
Amatorka

Conflicts:
	library/src/jp/co/cyberagent/android/gpuimage/GPUImageFilter.java
	sample/src/jp/co/cyberagent/android/gpuimage/sample/GPUImageFilterTools.java
GPUImageLookupFilter.java
Clean up formatting
Clean up of the code (remove copy paste code, unused variables, ...)
Add headers
Fix: TwoInputFilter: Saving picture with blend does not apply the 2nd texture
Move Blend filter into single classes (as in GPUImage for iOS)
Merge TwoInputFilter goodness from @mstrengis with some small changes
closes #8 closes #13