am 9a81736: Add the ability to specify the onClick handler with XML.

Merge commit '9a81736176f507489f262344b6e3d55bbe53be7c'

* commit '9a81736176f507489f262344b6e3d55bbe53be7c':
  Add the ability to specify the onClick handler with XML. The new android:onClick attribute defines the name of the method in the Activity to invoke when the button is clicked. The method has to be public and get one View parameter.