Refactor: Topic#invite_by_email

Extract Topic#email_already_existas_for? and Topic#grant_permission_to_user
Fix failing spec due to missing variable in extracted method
Refactor: Topic#invite_by_email

Extract Topic#email_already_existas_for? and Topic#grant_permission_to_user
Fix failing spec due to missing variable in extracted method
Merge branch 'refactor-topic-invite-by-email' of github.com:cored/discourse into refactor-topic-invite-by-email
adds unit tests for Discourse.View
Refactored Topic#limit_topics_per_day to reduce code climate complexity

Extracted  1) #apply_per_day_rate_limit_for, method as generic
RateLimiter , 2) #limit_first_day_topics_per_day as a separate method,
3) Added User#added_a_day_ago?, 4) Fixed private methods indentation.
Support for MDTest
FIX: New line after blockquote
FIX: Heading with style
another speedup for the BackfillPostUploadReverseIndex migration
add a sitesetting to enable the CleanUpUploads job
When system flags users as sockpuppets, show a reason in the admin flags ui
unit tests for Discourse.ContainerView
removes unused return statement from Discourse.ContainerView.attachViewWithArgs
FIX: Nokogiri bugs in certain environments
Update Vagrantfile and docs/VAGRANT.md for new box
Post Expansion enhancements
Extra comma
Two Column User View
FIX: Smoke test failure