Adds GL namespace. Deprecates the `ccGLFunctionName` functions. New functions are `GL::functionName`
Also, converts the class `DrawPrimitives` into a namespace
Transition::ORIENTATION_XXX -> Transition::Orientation::XXX
Image::FORMAT_XXX -> Image::Format::XXX
Image::_function() -> Image::function() // private methods should not start with '_'
DrawPrimitives::drawColor() -> DrawPrimitives::setDrawColor()
And fixes Premultiplied Alpha in PVR v3 images
And tests are updated with the new functions