Bug 862842 - Update autoresponder email text & reply-to
Bug 862842 - Add Webmaker Mentor list signup to /contribute

When users sign up on https://mozilla.org/contribute and select "Education"
from the drop down list they should be subscribed to the Webmaker Mentor
mailing list. If they select any other interest, they should be subscribed
to the about:mozilla mailing list.
Merge pull request #1101 from jbuck/contribute2