The text field's delegate is no longer changed; this allows normal delegate methods to be used.  Instead, an observer is added for the relevant `NSNotification`,  `UITextFieldTextDidBeginEditingNotification`.
Added support for an Integer type (`BSTextFieldFormatInteger`), which hides the decimal button.
Added support for customizing the title of the NEXT button
Properly support the UITextView delegate method `textField:shouldChangeCharactersInRange:replacementString:`
Added a helpful comment
Merge pull request #1 from evands/master

Text view delegate support and some customization options