* libgimp/Makefile.am: add gimpmath.h

* app/gtkwrapbox.[ch]
* app/gtkhwrapbox.[ch]: wrapbox widget from gle

* app/Makefile.am: added those files

* app/interface.c: use an hwrapbox for the toolbar. Still not perfect
yet, working on it.

* app/gimpdrawable.c
* app/about_dialog.c
* app/airbrush.c
* app/blend.c: some minor code cleanup

-Yosh