draw_ctx, moved it to gui_util.c, and made it a global variable
- moved drawing logic for hovering and dragging into dedicated state machine
in gui_over.c
- hovering now uses a pixmap to restore the background instead of redrawing
- moved hover drawing functions from gui_inst.c to gui_tools.c
- made hover circle thicker
git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5405 99fdad57-331a-0410-800a-d7fa5415bdb3