Submissions by form

First commit adds faceting capabilities to ESQuery ( @emord  fyi).  Second commit switches Submissions By Form to use one faceted query per form (which is then memoized).  The old version performed a separate couch query per each form per each user.  This was causing timeouts on the request.
http://manage.dimagi.com/default.asp?130842#737425
Oh nice, I didn't know you could do that.  I think I saw someone do this with backslashes a while ago and I've just been doing it like that ever since.