This patch enables memory warning support on ASRangeController by default
This patch enables memory warning support on ASRangeController by default

It also fixes a couple subtle bugs:
1. If a range controller update was in flight and you were manually setting the range
mode, you could actually clear out the range mode by calling updateCurrentRangeWithMode:
This is fixed by setting _didUpdateCurrentRange = YES if _needsRangeUpdate is YES.
2. Calling setNeedsUpdate after calling updateCurrentRangeWithMode: can cause the
current range mode to get cleared out. This is because updateCurrentRangeWithMode:
will not set _didUpdateCurrentRange if _currentRangeMode == rangeMode.

rmls/AsyncDisplayKit,aaronschubert0/AsyncDisplayKit,maicki/AsyncDisplayKit,tomizimobile/AsyncDisplayKit,harryworld/AsyncDisplayKit,tomizimobile/AsyncDisplayKit,tomizimobile/AsyncDisplayKit,harryworld/AsyncDisplayKit,chrisdanford/AsyncDisplayKit,lappp9/AsyncDisplayKit,aaronschubert0/AsyncDisplayKit,JetZou/AsyncDisplayKit,lappp9/AsyncDisplayKit,chrisdanford/AsyncDisplayKit,tomizimobile/AsyncDisplayKit,rmls/AsyncDisplayKit,maicki/AsyncDisplayKit,maicki/AsyncDisplayKit,maicki/AsyncDisplayKit,flovouin/AsyncDisplayKit,rmls/AsyncDisplayKit,rmls/AsyncDisplayKit,JetZou/AsyncDisplayKit,aaronschubert0/AsyncDisplayKit,chrisdanford/AsyncDisplayKit,JetZou/AsyncDisplayKit,harryworld/AsyncDisplayKit,maicki/AsyncDisplayKit,aaronschubert0/AsyncDisplayKit,JetZou/AsyncDisplayKit,flovouin/AsyncDisplayKit,lappp9/AsyncDisplayKit,romyilano/AsyncDisplayKit,rmls/AsyncDisplayKit,romyilano/AsyncDisplayKit,flovouin/AsyncDisplayKit,harryworld/AsyncDisplayKit,chrisdanford/AsyncDisplayKit,lappp9/AsyncDisplayKit,JetZou/AsyncDisplayKit,tomizimobile/AsyncDisplayKit,flovouin/AsyncDisplayKit,harryworld/AsyncDisplayKit,romyilano/AsyncDisplayKit,aaronschubert0/AsyncDisplayKit,romyilano/AsyncDisplayKit,flovouin/AsyncDisplayKit