Merge pull request #48 from iOSLabs/master

Support custom content view scale & offset when show menu
Update code formatting
Update contentViewScale on pan gesture
Version bump (3.1.7)
Expose _contentViewController & _menuViewController to subclass

Enable subclass creating its own initialization method to init
contentViewController & menuViewController like
-initWithContentViewController:menuViewController: method does:
Use _XXXViewController instead of self.XXXViewController.
Merge branch 'master' of github.com:romaonthego/RESideMenu