This adds cogl_texture_2d_sliced_new_from_bitmap/data/file apis in
preparation for removing the cogl_texture_new_from_bitmap/file apis that
are considered a bit too magic, but we don't want to loose the
convenience they have.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 218da8e1349d7658f45c6933b9736c0d32941b8b)
Conflicts:
cogl/cogl-auto-texture.c
061240ef2a
