Finished initial support for UISwitch
Cleaned up naming and placement of some UISwitch code
Added initial autoupdate support
Elminate UITextAlignment deprecation warnings.

Use NSTextAlignment on iOS 6 and UITextAlignment on iOS 5. Solution based
on examples from http://stackoverflow.com/q/11920321/79202.
Add assert to ensure a file exists.

Took me a while to track down that I had a typo in my file name, because the
exception thrown was from NSRegularExpression. So add an `NSAssert()` to save
other future developers from themselves.
Removed deprecated render:onDrawRect:withClass from NUINavigationBarRenderer
Made NUISettings setAutoUpdatePath return void
Improved support for background-* changes during autoupdate
Updated podspec to 0.2.3
Added autoupdate directions to the README
Merge branch 'autoupdate'
Added support for more background and border properties to BarButton
Added +[NUIGraphics backButtonWithClass:]
Made insets larger for BarButtons
Deprecated UI* style classes, added BarButtonBack, rendering back buttons with +[NUIGraphics backButtonWithClass:]
Improved Button's support for text-shadow-color
Merge pull request #43 from theory/assert-file

Add assert to ensure a file exists.
Merge pull request #42 from theory/alignment-deprecation

Elminate UITextAlignment deprecation warnings.
Update README.md
introduced an -insets value for every style able image