Use arrayTransforms lib in release editor

Behavior after patch should be functionally equivalent to previous
behavior, but using the arrayTransforms library for increased
efficiency due to not having to re-calculate expensive loops inside
computed observables.
Edit incorrect comment

Recording lengths are now calculated automatically.
Remove VARTIST_ID constant

It's useless because the GID is always set.
Use the loop binding in the RE where possible
Merge remote-tracking branch 'bitmap/mbs-7741' into beta

* bitmap/mbs-7741:
  Use the loop binding in the RE where possible
  Remove VARTIST_ID constant
  Edit incorrect comment
  Use arrayTransforms lib in release editor
Update pot files using current code and production database.
Update translations from transifex.