add pixels property to FBO, to get access to rgb buffer for saving texture
Merge branch 'fbo_pixels' of /Volumes/TOMTOM/kivy/ into fbo_pixels
core/image: add save() method on loader and image. Only pygame core provider implement the saving.
core/image: implement save() for PIL
core/image: implement ImageIO save
core/image: fix imageio for png and jpeg output
core/image: add documentation, and support saving Image(texture).save()
graphics/texture: add save() for TextureRegion as well, and more documentation.
Merge branch 'fbo_pixels'