CoglPixelFormat is not a good way of describing the internal
format of a texture because it's too specific given that we don't
actually have exact knowledge of the internal format used by the driver.
This makes cogl_texture_get_format private and in the future we'll
provide a better way of querying the channels and their precision.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit ffde82981f22bd0185a7f33e1e6e1479f4c295b8)
Note: Since we can't break API compatibility on the 1.x branch this adds
a cogl/deprecated/cogl-texture-deprecated.c file with a
cogl_texture_get_format() wrapper around the private api. This also
moves the cogl_texture_get_rowstride() and cogl_texture_ref/unref()
functions that were previously deprecated into cogl-texture-deprecated.c
