[TIMOB-11876] Update background image code
[TIMOB-11876] Code cleanup
Merge branch 'master' of git://github.com/appcelerator/titanium_mobile into timob-11876
[TIMOB-11876] Add support for shadowImage and hideShadow properties
[TIMOB-11876] Make shadow image resizable.
[TIMOB-11876] Doc Update
[TIMOB-11876] Do not update when navbar when window not visible
Merge pull request #4750 from vishalduggal/timob-11876

[TIMOB-11876] Support for custom shadow image of nav bar