Blender Git Loki

Another step in the undo evolution.

- Made unified API for undo calls, to be found in space.c
BIF_undo_push(char *str)
BIF_undo(void)
BIF_redo(void)
These calls will do all undo levels, including editmode and vpaint.

The transition is work in progress, because mesh undo needs recode.

- New global hotkey CTR+Z for undo
Note: 'shaded draw mode' still is SHIFT+Z, the old CTRL+Z was to recalc
the lighting in shaded mode, which already became much more interactive,
like during/after any transform().
Recalc hotkey now is SHIFT+ALT+Z

CTRL+<any modifier>+Z is redo.

- For OSX users; the Apple-key ("Command") now maps to CTRL as well. This
disables the one-mouse-button hack for rightmouse btw, will be fixed in
next commit. At least we can use Apple-Z :)

- Old Ukey for undo is still there, as a training period... my preference is
to restore Ukey to "reload original data" as in past, and only use new
CTRL+Z for undo.

- Added undo_push() for all of editobject.c and editview.c. Meaning we can
start using/testing global undo in the 3d window. Please dont comment on
missing parts for now, first I want someone to volunteer to tackle all of
that.

- Since the global undo has a full 'file' in memory, it can save extremely
fast on exit to <temp dir>/quit.blend. That's default now when global undo
is enabled. It prints "Saved session recovery to ..." in console then.

- In file menu, a new option is added "Recover Last Session". Note that this
reads the undo-save, which is without UI.

- With such nice new features we then can also kill the disputed
Cancel/Confirm menu on Q-KEY.

- Added fix which initializes seam/normal theme color on saved themes.
They showed black now.... (Note: that's in usiblender.c!)