Add scaffold for /contribute controller
Add /contribute homepage
Add /contribute/license page with Tufts deposit license
Add routing and redirects to always take regular (non-admin) users to the landing page at /contribute
Add dynamically generated select list of deposit types on /contribute landing page for authenticated users
Support restful selection of deposit types for new self deposit creation.

Instead of passing deposit type via a post, convert it to a query string.

eg. /contribute/new?type=3
Merge pull request #65 from curationexperts/contribute_take2

Adds contribute controller with contribution landing page and license page