added 2d textures fxs

add BRDF w environment

changed vars names

added snapshots

fixed shadow mapping readme

added proper documentation

added in vec4 color functionality to shadows

updated TODO.md

removed ofxShadersFx from cube map, displacement, brdf, Geom, and Tessellation

removed ofxShaderFx from normal mapping

removed ofxShaderFX from phong example

unify in-out variables names

added ShadowMapping

added NativeGL example

fixed Tessellation example