Add audio player

See merge request !4

Without it, Chrome stretches the image...

This is to add the current user.

This adds a favorite notification.

Kind of wonky. Would be better if we used the AS endpoints.

This now uses nearly only mutation, to take advantage
of vue's mutation tracking.

Feature/image upload improvements

See merge request !2

Feature/retweet

See merge request !1

Apply different styles to reply, retweet and favorite buttons

Expand API service for retweet