MMDrawerBarButtonItem improvements

- touch/highlight-state support in iOS7
- added initWithCoder: for xib/storyboard support
- touch-action sender is now the bar button item itself vs a UIButton
oops fix - correct action/target for iOS6 code path
Merge pull request #120 from klundberg/master

Resolving clang analyzer issues found in Xcode5
Fix for issue #123: MMDrawerOpenCenterInteractionModeNavigationBarOnly fails if navigation controller's toolbar is shown.
Merge remote-tracking branch 'tomswift/master' into 119
Clean up
Merge pull request #124 from tbveralrud/master

Fix for issue #123
Update README.md

The subspec has a 's' at the end MMDrawerVisualStates not MMDrawerVisualState
Fixed incorrect rect conversion
Fixed another incorrect rect conversion
Merge pull request #158 from joneswah/patch-1

Update README.md
Fixes a performance regression when disabling the shadowPath property on the center view.
Added shadow optimization for when displaying shadow path to prevent unnecessary path calculations.
Update README.md

Small typo
Updating cocoa pod badge to https to avoid Github image caching
Merge pull request #191 from ScottBouloutian/patch-1

Update README.md
Updated readme for #184
Merge pull request #209 from mutualmobile/readme_updates

Updated readme for #184
Merge pull request #177 from mutualmobile/shadow-performance

Fixes a performance regression when disabling the centerView shadowPath
Merge pull request #163 from antonholmquist/original

Fixed incorrect rect conversion