Filters

Marketplace sort/filter now works. 

You can sort by popularity (currently this means rating, but we could make our own ranking)....
![image](https://cloud.githubusercontent.com/assets/1919535/4467106/33b40ae8-48ec-11e4-995b-c6517234494d.png)

By A-Z....
![image](https://cloud.githubusercontent.com/assets/1919535/4467109/4414c36e-48ec-11e4-847a-93226be93bb7.png)

Or by category....
![image](https://cloud.githubusercontent.com/assets/1919535/4467118/5e8eb38a-48ec-11e4-987b-9b3b5fda3eff.png)


Pretty nifty.
So agile means changing quickly. Lets go with a hardcoded list, then make a story to make it dynamic.  Here are the list of current categories in production. Make it so:

<children>
    <group>Academics</group>
    <group>Administration</group>
    <group>Advisor</group>
    <group>Applications</group>
    <group>Campus Apps</group>
    <group>CourseGuide</group>
    <group>Development</group>
    <group>Finances</group>
    <group>Help</group>
    <group>Home</group>
    <group>Instructor</group>
    <group>Library</group>
    <group>News</group>
    <group>Notification</group>
    <group>Research</group>
    <group>Services</group>
    <group>Student Learning</group>
    <group>Student Services</group>
    <group>Test</group>
    <group>Work</group>
  </children>