[networkcontrollers] Fix build break caused by refactoring of UIView categories.

Closes #257.
[attributedlabel] Add NSMutableAttributedString+NimbusAttributedLabel to the static library.

Closes #251.
[attributedlabel] Implement UIAccessibilityContainer.

NIAttributedLabel's links are now accessible.

Closes #248.
[core] Add snapshot rotation.
[core] Rename NISnapshotRotation protocol to NISnapshotRotationDelegate.
[catalog] Add snapshot rotation example. Works on iOS 6 and higher only.
Merge branch 'ios6'
[attributedlabel] Avoid potential bug in accessibility when no implicit links exist.
[catalog] Better docs for the snapshot rotation table view controller.
[catalog] Forgot to revert my own experiment, hah!
[core] Don't build the iOS 6 functionality with older SDKs.
[core] Add resizableImageWithCapInsets:resizingMode: to SDKAvailability.
[core] Add typedef of UIImageResizingMode.
[core] Finally got Xcode 4.3 building and verified all pre-iOS 6 SDK fixes.
[models] Remove "weak" reference for iOS 4 compat.
[attributedlabel] Docs cleanup.
[launcher] Docs cleanup.
[models] Remove redundant readwrite property descriptor.
[models] Fix unit tests.
[core] Update namespace header.