Updates to trading interface 355

Makes Buy/Sell headings larger
Removes select2.css from index.html to improve select2 style/use smart-admin styles
Reduces the space between label and input on buy/sell forms
Removes the scroll bar space in Chrome (unless necessary) on the right side of History, Open Orders, Sell Orders, Buy Orders tables.

![screenshot 2014-08-29 14 35 54](https://cloud.githubusercontent.com/assets/8549493/4094838/77e9717a-2fac-11e4-8963-8e89acfb39b4.png)