Extract methods to improve flog score of TopicView
Generate avatars with transparent background

Generate avatars with transparent background (for .png images) or with white background (for others).
only the host part of an email address is case insensitive
Replace Clockwork with Sidetiq
Add ScreenedUrl. Rename BlockedEmail to ScreenedEmail.
Merge pull request #1330 from ZogStriP/emails-can-be-mixed-case

only the host part of an email address is case insensitive
Finish renaming blocked emails to screen emails
Merge pull request #1328 from abbat/patch-1

Generate avatars with transparent background
FIX: performance regression on activity streams
Merge pull request #1317 from novemberkilo/master

Extract methods to improve flog score of TopicView
Merge pull request #1309 from stephankaag/sidetiq

Replace Clockwork with Sidetiq
Merge pull request #1331 from ZogStriP/fix-avatars-on-activity-stream

FIX: performance regression on activity streams
PNG Files optimization
Update client.zh_CN.yml
clarify on invite friends
default relative dates to 30 days vs 14
Refactors UserEmailObserver to improve Code Climate score

- Extracts certain logic to private methods and remove unnecessary
comments
- Extracts email enqueueing methods into a separate class
- Fix specs involving UserEmailObserver to call #after_commit instead
of the specific methods
Clarify install doc wrt how to create databases
Merge pull request #1374 from manzoid/install-doc

Clarify install doc wrt how to create databases
Merge pull request #1370 from ofgeek/patch-2

Update client.zh_CN.yml