* New field added in the `video` table + migration script
* `publishedAt` updated to NOW when privacy changes from private to
public/unlisted (default = NOW)
* Models updated to handle the new attribute
* Client interface updated to use `publishedAt` instead of `createdAt`
except in My Account > My Videos view
* Update video duration string to show hours when >= 60min
* Only show hours in duration when relevant
* Fix problem with ternary expression
* Remove accidentally commited package-lock.json
* Fixes#156: Filter out the video being watched from the list of other videos of the same author;
* Fixes#167: in the video view, hide the author's domain when it's from the current host;
* Fixes#171: Allow undoing a like/dislike;