Support single redis DB.
Various cleanups to Ubuntu installation instructions:

* Avoid editing /etc/apt/sources.list add nginx repo, instead create
  /etc/apt/sources.list.d/nginx.list

* Avoid editing /etc/nginx/nginx.conf, instead put server_name_hash_buckets
  setting into discourse.conf

* Proper-case Discourse when it is referring to the product name, so that all
  the lowercase references are to the user created during the installation
Address @Supermathie's concerns in PR1430
Locate the Puma config file.
Update puma.rb
Russian translation (actual version)
FIX: Title text should be correctly escaped since we are generating a raw html.
Update client.zh_CN.yml
tweak RSS elements for W3C compatibility

installation needs to have contact_email set in the admin settings in
order for that installation to have truly valid feeds
Don't auto-close a topic too soon in PeriodicalUpdates
Revert "Got rid of buggy yepnope spaghetti, however mobile detection really should be driven from the server."
Revert "Re-apply with fixes: Stop using user agent to detect mobile devices. Use a media query and yepnope to load the appropriate css and customizations."
Shorter instructions for the name field in the signup form.
shorter text is better text
don't warn unless in production
Added some missing references, see https://github.com/rails/rails/issues/12982
stop messing with asset pipeline defaults
stripping postfixes is wasteful and uneeded. It messes up our build
respect newlines in About Me on profile page
Add setupTopicController event
Merge pull request #1748 from alxndr/profile-bio-newlines

respect newlines in About Me on profile page