2.5

2.5

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.