10598 theme settings

This is a fairly large commit which removes the default themes from our install profile and replaces them with theme settings.

To test, install the profile from a fresh, enabling the default content. Once installed, go to appearance. You should only see one enabled theme - "aGov". Edit the theme's settings and you should be able to switch between the various colour schemes.

This branch also features a new STARTERKIT theme (and a drush command) to help user's get up and running with their own theme (and own css).