Improve general admin page layout

Improve layout of General admin page tab. 

![Google ChromeScreenSnapz012](https://f.cloud.github.com/assets/1079437/394790/0afbc7c6-a7d5-11e2-97b8-6192400f7e23.png)

Mostly this was adding labels, removing colons on labels, and tidying up the target market multi-select.