[TIMOB-15855] iOS: refactor subview insertion based on zIndex
Merge branch 'master' of git://github.com/appcelerator/titanium_mobile into timob-15855
[TIMOB-15855] Code Refactor
Merge pull request #5443 from vishalduggal/timob-15855

[TIMOB-15855] iOS: refactor subview insertion based on zIndex