Create _default.css, state goals and current state

I've only just started customising the 'Unicorn' theme of our Ushahidi install - the home page so far mostly, the navigation a little bit. Also the decision to go whiter and brighter than footscraymakerlab.com - more utilitarian.

Next steps are to fix up the category, post and submit report pages, as well as put more useful controls on the front page.