Blender Git Loki

2.5: Image window, some small changes:

* Added notifier for edited images.
* Fix main region emboss drawing when showing render.
* Don't go fullscreen with fileselect for now to work
around context getting lost, so open/replace works.
* Save operators are more complete now, but still lack
confirmation and choosing image type.
* Pack operators work correctly now (but not unpack).
* Setting white/black point for curves.
* Time cursor for record composite.