BUGFIX: we should not store absolute urls for locally uploaded avatar templates

Highly recommended to run: `RAILS_ENV=production bundle exec rake avatars:regenerate` to fix the avatar templates stored in the database.
Add spinner when authenticating with 3rd party. Also handle when popup window is closed without making a callback.
FIX: version check job when no versions are returned in json
Improved Embedded templates slightly.
Remove remaining code for two-column categories page
don't muck with production.rb, no longer supported
BUGFIX: show uncategorized in tracking etc
BUGFIX: allow emptying of lists of watched / tracked
BUGFIX: page scrolls when clicking on [x]
BUGFIX: rss feed link for topics has been broken ever since we upgraded rails