Some improvents

- Added options to dismiss on inner tap and dimiss on passthrough tap (`dismissOnTap` and `dimissOnPassthroughViewTap` BOOL properties).
- Added `^dismissCompletionBlock(WYPopoverController *dimissedController`) block property. Can be used in addition, or in place of, the delegate's popoverControllerDidDismissPopover: method.
- Removed old unused touch code