Cleanup in area/region management - more intelligence in area management for adding handlers and setting data correct. Space/Region type callbacks only have to do own things. - added option for adding default handlers to areas/regions. (flag in type definition) - ensured that region-types store the minsizes for regions. - added boundbox check for handlers; note that it accepts pointer to boundbox, because handlers don't get reset on area-resizing or view changes. Example: view2d handlers use mask rect. - handlers get now added on correct context levels (example frame change also worked in header) - removed ->refresh() callback. Context refreshing is Listener. - the ->init() is being called on all WM level actions, also after a file read, moving areas, re-opening areas etc. - fixed bug: crash on exit was caused by cleaning up Screen too late. - UI_view2d_size_update() removed from draw callback, is init() - regions now store (winx, winy) subwindow size.