Added support for slide from right.

- This change adds support for opening the side menu from the left or the
  right. This is configurable via the MVYSideMenuOptions object provided during
  initialization.
Added a delegate for notifications open/close events.

- Added the MVYSideMenuControllerDelegate so that another object can be informed
  of side menu open and close events.
Merge pull request #1 from wcwynn/master

Open from right support