MUMUP-1402: Collapsible Sidebar

Youtube-esque collapsible sidebar. The sidebar is shown by default, since it I don't think it would be smart to relegate the navigation for the site to a small menu icon by default. 

Still need to add the ability to remember whether sidebar is open or closed per user. I believe that's on the uPortal side though?

### Notable tweaks:
- Mobile menu now has this black and white image of campus instead of the crest
- Quick links added to the sidebar as a concept for how this could look. I am personally a huge fan of this approach, but I know Phyllis had reservations about it.
- Marketplace icon is a star. Cog icon didn't really make sense to me.
- When sidebar is minimized, the width of the main content is col-sm-11, rather than col-sm-10. Hurray for more real estate!

I took some liberties with the style, let me know if you have any thoughts/concerns/suggestions for them.

### Screenshots:
![image](https://cloud.githubusercontent.com/assets/1919535/5480671/03ac913a-860e-11e4-92f6-13a6fb0ac515.png)

![image](https://cloud.githubusercontent.com/assets/1919535/5480683/1c93eafe-860e-11e4-8f2d-69a83bcdab8b.png)

![image](https://cloud.githubusercontent.com/assets/1919535/5480687/2cb2b1cc-860e-11e4-876b-b592e03189fe.png)

![image](https://cloud.githubusercontent.com/assets/1919535/5481366/c90f2e40-8615-11e4-9a44-7b5ac6f96e54.png)


> Marketplace icon is a star. Cog icon didn't really make sense to me.

Much to be said for clear icons!  I get the aversion to `fa-cog` for this -- it's not so much settings generally, which is what that cog tends to evoke.

I'm not entirely feeling the selection of `fa-star` though.  Star evokes Favorites -- I click a star to favorite something specific or in navigation to go to the stuff I've favorited (starred).  I don't click a star to go find new things to star.  Cf the way Trello uses a star icon to adorn the section header for Starred Boards:

![starred_boards_adorned_with_star](https://cloud.githubusercontent.com/assets/952283/5490667/c0602e06-8698-11e4-9865-760f70c26317.png)

Ideas:  

 * `fa-binoculars` to go on safari to find an App?
 * `fa-archive` to peruse the box-o-Apps?
 * `fa-folder` to go look in the folder of Apps?
 * `fa-plus-square` to evoke *adding* something?

I'm not loving any of my ideas here, but I'm not loving the star used in this way either. :/