#8 - Add delegates for alertViewWillShow, alertViewDidShow, alertViewWil...

...lDismiss, alertViewDidDismiss

Since the AMSmoothAlertView isn't a straight drop-in replacement of UIAlertView, these will come in handy, for example, when certain UI components need ```component.enabled = NO```, especially if that component triggers an alert, because multiple alerts will just start stacking on top of each other.

Since the keyboard stays on top of the blurred image view, if I hit "Go" on the keyboard and that triggers an alert, I can inadvertently make a bunch of AMSmoothAlertViews start appearing and make an ugly stack of them.