Adds Retina HD support to ImageLoader

JIRA ticket: https://jira.appcelerator.org/browse/TC-4752
[TIMOB-17734] Set up correct scales and filenames
[TIDOC-1890] Add note about forcing orientations
[TIMOB-17665] Updating ti.map-iphone module
Merge pull request #6150 from jonalter/TIMOB-17665-3_4_X

[TIMOB-17665] Updating ti.map-iphone module
Merge pull request #6147 from vishalduggal/timob-17734-34X

[TIMOB-17734] (3_4_X) iOS: ImageLoader doesn't support @3x
Merge pull request #6149 from bhatfield/tidoc-1890-3_4_X

[TIDOC-1890](3_4_X) Add note about forcing orientations
[TIMOB-17141] Reload data on frame size changed
Merge pull request #6153 from vishalduggal/timob-17141-34X

[TIMOB-17141] (3_4_X) Reload data on frame size changed