driftyco/ionic — pull request #607 by ajoslin (2014-02-14 19:12:43+00:00)
Title: fix(navBar): animations work properly

Starting a couple of versions ago, animations in navbar stopped working.
I took this as a chance to fix this, and do a refactor to make the code
more modular and testable.

Additionally, all of the navbar attributes are now interpolated and flexible (so for example people can change their back button icon at runtime if they do `back-button-icon="icon-{{myIcon}}`.