Fixes:
- Usage of UIScreen in -[ASDisplayNode init]
(the offending individual will be prosecuted)
- #38: Proper teardown of nodes owned by ASTableView / ASRangeController
- #34: Fix infinite recursion in very rare subclassing scenario
- #30: Avoid animating cell and section additions to ASTableView
- #19: Set a more reasonable default for maximum display concurrency
r=nadi