Fixed bugs, added effective rect handlers.

- Fixed bugs causing some views to be improperly resized when collapsed.
- Added block handlers for split view effective rects.
Added block handler for divider drawing
Merge branch 'master' of github.com:kainjow/AGNSSplitView into kainjow-master

Conflicts:
	AGNSSplitView.h
	AGNSSplitView.m
	AGNSSplitViewDelegate.m