rxAppSearch && rxAccountSearch

Two new directives (one reusable, one single use) for easier searching for nav menus.

Use in Demo:
![image](https://cloud.githubusercontent.com/assets/706039/2783766/54396f9e-cb31-11e3-9fe3-0c1956f66c20.png)

Use in Cloud Atlas:
![image](https://cloud.githubusercontent.com/assets/706039/2783761/477d5e82-cb31-11e3-855c-5210532ffded.png)