FEATURE: new "disable_edit_notifications" site setting

Should be used whenever you activate the "download_remote_images_to_local" site setting to prevent users from receiving a lot of edit notifications from the system user.
FIX: in import scripts, fix a case where post author lookup fails for some reason
Revert "Revert feature till it works."

This reverts commit 1e9f3fa5934f645113b60646f039c22d29a4a8a9.
REFACTOR: Keyboard Shortcuts should send their actions directly to
posts, not by activating clicks on buttons.
REFACTOR: Only show ellipsis if there is more than 1 thing behind it.
Always show your own edit button
FIX: Reply button broke
FIX: Upgrade onebox to avoid too many refreshes with timestamps
Validate username site settings
FIX: wrong i18n key on Take Action button
FEATURE: User Bookmarks Menu
BUGFIX: enable the 'relative timestamp' share dialog on mobile view
A little extra robustness for the post stream
Merge pull request #2436 from ArmedGuy/master

Deboxify topic-map
bigger category stat numbers
Omit Needless Words
SECURITY: fix XSS
BUGFIX: not binding correctly to notifications that popped up AFTER element was inserted
BUGFIX: not clearing blue notifications correctly when you have a PM
BUGFIX: fragile test corrected, stubbing is not needed here.