Fix incorrect email links

Actually ended up being a fairly big oversight.  Whoops.  Had to add the ability to get to the "send to backpack" page without a claim code (using a shortname/email combo instead), since we're using this page for all badges, and not all badges have claim codes.

This also fixes the short/long description split by making it more tolerant of badges with only one description.  In that case, both the long and short description will be the same (instead of the long description being blank).