Use redis for sessions instead of memcached.
Add Redis dependency to carton.lock.
Update documentation to say redis is required.
MBS-4419, expire release editor sessions.
Turn MusicBrainz::DataStore into a role and remove dead code from it.
Merge branch 'beta' into mbs-4419

* beta: (357 commits)
  Quick temporary instructions for recent carton versions.
  Update translations from transifex.
  Recompress all the images, for slight gain.
  Update languages from transifex.
  MBS-5960: url-escape more things Ian forgot in writing the wikipedia extract code
  MBS-5956: stop comparing undef as a number in Edit Medium
  Update instruments.pot partway -- only add new instruments.
  Update the .pot files that don't require migration scripts.
  MBS-5954 Confirm revoking OAuth access
  Do not compare with $args->{fmt} if it is not initialized.
  MBS-5955: HTML::FormHandler, cursed be its name, won't allow localize_meth while overloading a field definition
  Fix tests: add missing comma in Form::Merge
  Update .po files from transifex.
  Update .pot files.
  MBS-5945 Do not silently fail when there is an invalid URI in the input, but the user switched to "Installed Application"
  Allow any HTTP or HTTPS URL (e.g. localhost is OK, FTP is not OK)
  MBS-5946 Remember authorization of trusted applications even in the online mode
  MBS-5939 Do not display empty tables, description of what are "authorized applications", link to the OAuth documentation
  Changing the name of the select thingy
  Change "Disc" to "Medium" when reordering mediums
  ...

Conflicts:
	lib/DBDefs/Default.pm
Merge branch 'mbs-4419' into beta

* mbs-4419:
  Turn MusicBrainz::DataStore into a role and remove dead code from it.
  MBS-4419, expire release editor sessions.
  Update documentation to say redis is required.
  Add Redis dependency to carton.lock.
  Use redis for sessions instead of memcached.