Expose accessibility label and hints.
Improve animations.

Add a placeholder image property to JTSImageInfo. Improve animations when scaling to or from a cropped reference rect. Improve status bar handling..
Fix status bar bug.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Sample App/JTSImageVC/JTSImageVC.xcodeproj/project.xcworkspace/xcshareddata/JTSImageVC.xccheckout
	Source/JTSImageViewController.m