Keyboard Notification Parsing

[nhgrif]

Currently, BaseCamp exposes a framesForKeyboardNotification(notification: NSNotification) which returns a tuple containing the start and end rects for the keyboard change.

This is not returning all of the possible information, and it's really clumsy to deal with the tuple return type.

The keyboard animation notifications include at least two other properties. One represents the animation duration, and the other represents the animation curve.

BaseCamp should add a KeyboardAnimation model object which looks something like this:

public struct KeyboardAnimation {
    public let beginFrame: CGRect
    public let endFrame: CGRect
    public let animationDuration: NSTimeInterval
    public let animationCurve: UIViewAnimationCurve
    public let animationOptions: UIViewAnimationOptions

    public init?(notification: NSNotification)
}