Add separator between days, don't display grey zero

[WIP] Port notifications to Bootstrap and add filters, port hovercards

Check if the hashtag is a link in function .hashtagify

This reverts commit 06ab4986, reversing
changes made to 3c4d8d95.

Conflicts:
	Changelog.md

Fixed "hovercard avatars misaligned in notifications drop-down"

Solved problem with hashtags inside markdown links

Add handle indication on search page, improve design

Added limit by max_time to photos#index for prevent "infinite photo stream"

Fix publisher broken after jquery upgrade

Show hovercards in the notification drop-down for users on the same pod

Conflicts:
	Changelog.md

Propose for fix #4638

Added Changelog line

Added Specs for testing if the reshared origin post is deleted and therefore not shown in the atom feed

Fix different button sizes in new publisher

Port publisher and bookmarklet to bootstrap

Fix plaintext mode for mentionable

Also slight refactors to it.

atom-feed content changed to html, use better post-title extractor

Valid atom feed. Also these features are partially included:
- http://activitystrea.ms/specs/atom/1.0/#activity.verb
- http://portablecontacts.net/draft-spec.html#anchor16

Fix aspect renaming after a regression caused by jquery upgrade

Fix avatar position in mobile notification

Fix drawer in mobile version

Remove the black background on menu badges.
Fix body content on screen width > 768px.
Start split of mobile css in different files in /mobile/