Implement "Willing to Vote" checkbox

Signed-off-by: Michael Casadevall <mcasadevall@soylentnews.org>
Add missing alter table for users_prefs

Signed-off-by: Michael Casadevall <mcasadevall@soylentnews.org>
Merge pull request #138 from NCommander/implement_willing_to_vote

Implement willing to vote