Merge pull request #1829 from dingpinglv/Iss4975_Spine

Issue #4975: update debugSlot computing for Canvas
Fixed #5042: Improve logic of CCLayer's setTouchEnabled
Merge branch 'v2.x' of https://github.com/cocos2d/cocos2d-html5 into v2.x
Merge pull request #1832 from pandamicro/v2.x

Fixed #5042: Improve logic of CCLayer's setTouchEnabled
Fixed #4975: rename sp.Skeleton.createWithFile to sp.Skeleton.create
Merge branch 'v2.x' of https://github.com/cocos2d/cocos2d-html5 into Iss4975_Spine