Integrating userscript functionalities in default user interface

Following the 2017 summit: some functionalities brought/improved by userscripts could (and should) be provided by the default interface, provided they do not change the UX too much or add too many risks for a beginner to create a mess.

At the summit were mentioned in particular:

On generic pages:

• make table columns sortable
• paste-a-date

On the relationship editor pages:

• propagate recording dates
• batch-set live/partial attributes on work-recording rel

On artist overview pages:

• display covers (not sure about that one since I don't use it)

On release overview pages:

• perhaps a light version of mass-merge recordings (e.g. working only on full tracklists?)
• show discid/aliases/cover art counter on tab headers

On edit voting page:

• hide all my edits
• group-vote for edits by the same editor/same timestamp (possibly only for auto-editors)