Carpools

The carpools CRUD functionality is here.  I also list an event's carpools on the event/show page, but each carpool has a show&edit page.  the new carpool page is routed as '/events/:event_id/carpools/new.'

Also, i fixed that thing in event with dates.

Also, I'm finally getting the mocha testing thing, so try check out that carpool test file.  I generate all the objects in the before() call so I never run into invalid pointers or calls to dbs that have already been cleared.  I think I might go into the other tests and refactor them like that if I have time later.