Better sidebar view pointInside filtering

We only want to restore the last view controller if:

- the menu is displayed
- the touch is not in the menu view controller
- the touch is in the current view controller

This allows one to implement a slide-over menu and let it be dismissed.
Fix pointInside:withEvent: detection
Fix const to object pointers
Less verbose code
Translate point to the subview coordinate system
Merge pull request #5 from streeter/touch-detection

Better sidebar view pointInside:withEvent: filtering