Support negative scaling of CCScrollView.
Not checking for it in CCScrollView::getViewRect causes intersectsRect calls (eg: to check if the touch was within the bounds) to return false.
Merge branch 'master' of https://github.com/cocos2d/cocos2d-x
Merge pull request #2495 from ptekchand/master

fixed #2116: Support negative node scales of CCScrollView.