Merge branch 'beta' of https://bitbucket.org/metabrainz/musicbrainz-server into mbs-6584
mbs-6584: removing unused code from controllers
MBS-6469: Allow creating example relationships without a name

Removes the Javascript check that the name field is not empty,
in order to allow editors to document example relationships
without having to give them a name.
MBS-6496: Do not use medium recordings when adding new discs in release editor

When a new disc is added in the release editor, the last disc in the
editor is cloned and all its fields are cleared. However, there
appears to be a slight mistake in this clearing - the 'id' field is
cleared twice.

I've changed the second reference to the 'id' field to
'medium_id_for_recordings', which is an id that is used to provide
recording association suggestions. Clearing this, the release
editor suggests that new recordings are created.
Add 'npm install' to production-deploy.sh
Merge branch 'mbs-6486' into beta
Merge branch 'mbs-6469' into beta
Merge branch 'master' into beta
Merge remote-tracking branch 'reosarevok/mbs-6584' into beta