增加移动版Header和样式表
Minor fixes

* add discourse to sudo
* add `bundle exec` on some calls
* inform user of NUM_WEB/sockets count for nginx config
Refactor: Topic#invite_by_email

Extract Topic#email_already_existas_for? and Topic#grant_permission_to_user
No sudo perm for user

Also changed order on informing user that he'll be encountering errors that needs admin access before calling `rvm`.
Fix failing spec due to missing variable in extracted method
User expansion loading improvements
Better unloading of Poster expansion
Changes to user expansion
Make date on User expansion gray
minor copyedit to reduce repetition on dialog
large refactor, ship a few columns from the user table into user_stats
defer view creation on so updates are not performed when people navigate to topics
bug fixes for user_stat extraction, decrease querying
refactors asyncTestDiscourse to bind context as self
adds unit tests for Discourse.debouncePromise
Don't show the user expansion on mobile
Make clickable area for progress much bigger on mobile
FIX: Invalid i18n string appearing at bottom of topic
FIX: If the user asks for 0 similar topics, don't show an empty box
Close notifications dropdown on mobile after you click something