Fix underscore template error.
Fix `=` spacing

Add user avatar to user selection

Milestones needed a none selector
Assignee needed unassign.

Added nice animations too.

Using respond to instead

Make add single and add multi work properly.
Multiple inputs for multiselect

Adds deselect still a WIP.

Clarify LFS configuration

A user on Twitter was confused (rightfully so) because LFS admin docs suggest you must set a storage path. In fact, Omnibus defaults to a very sane location. Add a comment to the snippet outlining the default.

See merge request !3388

Fix cancel button on issuable edit form

See merge request !3392

Comments on confidential issues doesn't show in activity feed to non-members

Closes #14568 

See merge request !3375