Update README with info about keeping up todate.
Create a theming system, and an initial theme.

[Closes #5]

Squashed commit of the following:

commit e78d0cd443c3ae90e780fbd2658002392f19fb20
Author: Matt Buck <github@matthewbuck.com>
Date:   Wed Aug 14 02:50:42 2013 -0500

    Remove unneeded stylesheet.

commit c1f4f493eddff6ea77fb9b5ce79990228f08529e
Author: Matt Buck <github@matthewbuck.com>
Date:   Wed Aug 14 02:50:25 2013 -0500

    Create a theming system.

commit d9338f2598beb2062778bdbc263edd98f8c76c3c
Author: Matt Buck <github@matthewbuck.com>
Date:   Wed Aug 14 02:28:54 2013 -0500

    Create a new 'Regal' theme.