Style updates: first pass!

- Removed most explicit widths in favor of filling container
- Added a mixin to remove duplication in font styles
- Consolidated styles in a few places
- Added a touch of branding in the header
- Added basic mobile optimization
- Added some user-specific copy edits
- Moved contents of `application.css` to `globe.scss` to be able to use sweet, sweet SCSS
- Probably other stuff?

![screen shot 2014-07-14 at 12 38 31 am](https://cloud.githubusercontent.com/assets/169222/3567166/cbbfefce-0b10-11e4-84ca-8a10c15638a3.png)

![ios simulator screen shot jul 14 2014 12 37 59 am](https://cloud.githubusercontent.com/assets/169222/3567159/ac6f3058-0b10-11e4-98c2-a649ec8b6bd0.png)