This patch removes some cpp Freestyle shaders that are unused and don't serve a real purpose any more.
The removed shaders are:
- BPy_ColorNoiseShader
- BPy_ColorVariationPatternShader
- BPy_StrokeTextureShader
- BPy_TextureAssignerShader
- BPy_ThicknessVariationPatternShader
- BPy_fstreamShader
- BPy_streamShader
and a few more that weren't even exposed to the Python api.