Temporarily fix freshmancircuit button url.

We allowed `www.freshmancircuit.com` to expire, this changes the domain
to the one given by strikingly: `http://circuit.strikingly.com/`
Add Freshman Circuit fall 2014 deadline.
Change comments
Merge pull request #35 from rgardner/add-freshman-circuit-deadline

Add freshman circuit deadline and fix broken url.