Fix select2 styles

:fork_and_knife: Just use SVG for select2 close toggle, add bottom margin to selections.

From

![screen shot 2014-08-07 at 4 12 05 pm](https://cloud.githubusercontent.com/assets/316507/3848368/364ef1d4-1e6f-11e4-828b-e2d89093ae31.png)

To

![screen shot 2014-08-07 at 4 15 31 pm](https://cloud.githubusercontent.com/assets/316507/3848416/9d66a54c-1e6f-11e4-8ef2-00407973eeb7.png)