Edit: Contributions: Show card on file

Show the type of card we have on file, and
the last digit. Let's not show the "last 4,"
as we don't need to expose that info.
Add entrance
Entrance: View the profiles specified

Set the entrance page to show the profiles
of the people specified in config.entranceUsernames.

A 'profile' is a photo, username, real name, and the
communities a person belongs to.

This design is meant for about two profiles, with a
profile-image width of about 270px.

The profile image is retrieved by /profile/:username/image,
which gets an attachment named "profile.jpg" from the CouchDB
doc associated with that :username.