Blender Git Loki

fix size slider not working for image space brushes (uv sculpt and image paint). This is due to not checking if unified settings are active as per recent commit. Reused the space_view3D PaintPanel utility class slightly modified for the image space to do the checks. I am not very happy with the duplication but I decided to keep it as is since I change bl_space_type and bl_region_type from the original class. Reviewed by Nicholas Bishop.