dismissKeyboardForField:onTouchForced:

[ADDED]     Method for installing a tap gesture recognizer for dismissing a field.
PearlOverlay improvements, scroll management, and lots of new utilities.

[FIXED]     +[PearlOverlay activeOverlays] now properly holds a strong reference to each active overlay so the application can reference his overlay weakly.
[ADDED]     PearlOverlay can now display either a message or a progress activity.
[ADDED]     PearlOverlay can now automatically dismiss the overlay after a certain time.
[ADDED]     Pearl variants of UIView and UINavigationBar that can ignore touches.  navbar can become invisible without hiding its children.
[ADDED]     Utility for creating a UIEdgeInsets from how a rectangle intersects another.
[ADDED]     Utility for converting between UIViewAnimationCurve and its equivalent UIViewAnimationOptions.
[ADDED]     Convenience method for starting block-based CALayer animations.
[ADDED]     -[UIView superviewOrSelfOfKind:] to find a type of superview.
[ADDED]     -[UIScrollView automaticallyAdjustInsetsForKeyboard] to automatically set a scrollview's insets when a keyboard appears by intersecting its screen frame with that of the keyboard.
[ADDED]     IfElse, a variant of IfNotNilElse which works with primitives but doesn't test against NSNull.
[ADDED]     Pearl*Queue* macros for much simpler queue scheduling.