Adds meaning to a featured category

The marketplace controller will send to the view a list of portlets considered "featured".  Featured portlets are portlets that are in the category of "Featured".  Here is the controller static variable:
![image](https://cloud.githubusercontent.com/assets/5521429/2769704/07423e50-ca55-11e3-9be6-ca54ef0fce83.png)
(show root category preference name snuck in the screen shot).

Anything in this category will appear in the featured section in the marketplace list page.  1 featured portlet will be centered.  2 will appear side by side. 3 will appear as 1 in the middle, 2 side by side, etc.  0 featured portlets will result in this entire section not appearing.  A set is returned to the view, so the ordering does switch.

![image](https://cloud.githubusercontent.com/assets/5521429/2769690/c1d1cd36-ca54-11e3-9e85-7f7f0b439609.png)

![image](https://cloud.githubusercontent.com/assets/5521429/2769762/98c5bd66-ca55-11e3-9928-d3b532aaee56.png)

![image](https://cloud.githubusercontent.com/assets/5521429/2769777/b99af218-ca55-11e3-971e-71b04099ae37.png)

![image](https://cloud.githubusercontent.com/assets/5521429/2769786/d0b70630-ca55-11e3-81f3-693a33e347e3.png)

![image](https://cloud.githubusercontent.com/assets/5521429/2769821/42b687b0-ca56-11e3-97ac-251cd7875636.png)


I admit the whole display isn't particularly appealing.  This is a starting point.

__NOTE__ the screenshots are from UW Madison's portal.  A few things not affected by this pull request look different.

__2nd NOTE__ There was a discussion if constructing a featured portlet list should be part of the controller or should be in the service layer.  Presented as being in the controller.  Thoughts welcome.