* Fix routing error in respond_with (didn't use /moderator namespace).
* Fix /moderator/posts/approvals.json response to return full
PostApproval object, not just a success/failure message.
* Simplify the javascript a bit (use $.post instead of $.ajax).
Mark all tag <input>s with a `data-autocomplete` attribute, instead of
hardcoding a list of html IDs to autocomplete in javascript.
This way should be less error prone. It fixes autocomplete in several places:
* Autocomplete for the search box on /posts didn't work in the
responsive layout. This was because /posts has two search boxes that
both have the id `tags`: one in the normal sidebar, and one in the
responsive tag list. $("#tags") only initialized autocomplete on the
first one.
* Autocomplete didn't work on the aliases or implications pages. This
was due to selecting the wrong html ids.
* Converts queries to use active record instead of raw sql. This ensures
that user objects are loaded by rails in the join, so that we
don't have to issue `User.find` calls to load users one-by-one.
* Use `.includes` to preload associations used in the view, to avoid
additional N+1 query problems (primarily, calls to link_to_user
also causing users to be loaded one-by-one).
Fix pool_versions exception if PoolArchive db isn't set up. Prefer
ActiveRecord over raw sql so we can get real user objects so that the
view can use link_to_user.
Fixes display of borders on the previews and such. Also fix the yellow
duplicate background not always working because Post#has_dup_tag? didn't
return a boolean.
