Ancient issue in making screendumps in Blender. It used to support making
dumps of popup menus, but that disappeared a while ago. However, when you
press CTRL+F3 in a menu now, Blender hangs in some eternal loop in ghost.
This commit fixes making menu screendumps (nice for docs!).
- press CTRL+F3 *twice* for an exact copy of a menu. (first press exits
menu, 2nd press opens filewindow)
- note, it is ALT+CTRL+F3 in OSX
- what is saved is only the topmost open level of a menu
- full-screen dumps work too by holding SHIFT extra.