Basic venue scaffold

no frills.
Basic style changes for venue pages

A bit of a cleanup and make it look slightly nicer.

Also added some tests to cover the two new methods on venue: cost_summary
and the addition of a to_s default so I can just pass the venue to link_to
Testing required addition of shoulda and mocha
Quick and dirty logo

Just a fancy-looking "V".
It'll do for now.
Update welcome page to point at venue list

plus some minor structural css massaging to make it a little nicer
Add UserVoice feedback tab and link

I've created an account on UserVoice for bienvenue
I've thus added a feedback tab and a footer-link which both point at
UserVoice.
You can add issues (ie problems) and ideas - and there's a forum for help
too.