New Number of Players Field Implementation with Radio Buttons

Please disregard all the commits except for the last one, I could not figure out how to get rid of them and they do not affect anything. 

Changes implemented with the last commit: 
  - The contents of `media-input.js` are now the same as the one in cvan/galaxy. 
  - The CSS for the number of players input field was removed as it is not needed.
  - The number of players input is now in the form of a radio button.
  - `settings.js` now has the `number_of_players` as a property.

The result looks like this: 

![screen shot 2014-04-06 at 12 00 01 am](https://cloud.githubusercontent.com/assets/4560085/2624469/08a14d5c-bd41-11e3-8224-bd2f5783d648.png)

And, the PR https://github.com/cvan/galaxy/pull/158 can now be closed and the branch [number-of-players](https://github.com/cvan/galaxy/tree/number-of-players) can be deleted as all of @cvan 's comments are addressed in this PR.