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
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.
unit tests for Discourse.ContainerView
removes unused return statement from Discourse.ContainerView.attachViewWithArgs
Update client.zh_CN.yml
Collapse user details when not viewing index view
Never show preview pane in composer on mobile.
4% speedup on our test suite
FIX: composer for creating a new topic on mobile
Add a message to flags created because of the newuser_spam_host_threshold site setting
Disable caching of site settings temporarily
Link large user avatar to user profile
FIX: User stream pagination
Version bump to v0.9.7.1