Merge branch 'less-colors' into beta

* less-colors:
  Change multiselect :focus to @highlight-table-row so it's actually visible.
  Slightly darker green for positive-light-bg
  Merge greys, merge a few other colors too.
  Remove now-unused rel-editor-dialog-border color.
  Initial attempt to merge greys.
  Image optimization.
  LESS colors: greygreygreygrey
  Update (track|)-(up|down).png, expand.png, and collapse.png for color change.
  Purge @re-unfocus-tab-text and @re-focus-tab-text, replacing with musicbrainz-purple and text-orange. Will fix up icons to the same purple in a separate commit.
  Merge @moved-cover-art-bg into @diff-new-highlight, as it's essentially just a diff.
  Remove @form-error-text, merge into @negative-text.
  Purge @re-addtrack-text, replace with @placeholder-grey
  Rename @diff- to be clearer
  Change @header-orange and @header-purple to @musicbrainz-orange and @musicbrainz-purple.
  Initial less-colors work from June.
Merge branch 'beta' of github.com:metabrainz/musicbrainz-server into beta
Update pot files using current code and production database.
Merge branch 'beta' into mbs-7077

Conflicts:
	root/static/styles/widgets.less
Update translations from transifex.
Merge remote-tracking branch 'bitmap/mbs-7077' into beta

* bitmap/mbs-7077:
  MBS-7077: beta: sizing issues with dialogs/autocompletes in relationship editor
Adding custom-made images
Show flags
MBS-5973: Display release group CAA statistics
MBS-7084: Update to_merge on /:entity/merge pages

The work on MBS-7057 meant that entities were only loaded from the
session once to avoid some odd state changed bugs. This meant that the
extra information loaded on the /:entity/merge confirmation page
was loaded, but never used in the actual rendered page as that
referenced a different variable.

This commit keeps most of the code the same, but on the merge confirmation
page we make sure to reset $c->stash->{to_merge} with the new set
of entities.
mbs-7086: fixing JSON for video recordings
Add edit_kind method (add/edit/remove/merge/other) to all edit classes

Necessary for MBS-1989
MBS-1989: Color-code edit header based on kind

Cancelled edits are light gray, closed edits are more grayish than their
open counterparts.

Thanks to nikki for the original "Colourful rainbow edit headers" user
script, upon which this is based on.
MBS-7081: Beta: disambiguation comments on inline search are barely readable
MBS-7085: update to remove primary_code warning now that area codes are always loaded
MBS-6915: Uploading multiple images in IE10 does not work as expected

IE10 caches the json blobs from previous requests. This makes it not
do that.
MBS-7073: Set the 'show_video' flag on artist overview

If the artist only has standalone recordings, then we should
conditionally show the 'video' column depending on whether or not any of
the standalone recordings are in fact standalone videos.
MBS-7044: Sort aliases by locale, then dates, then names
"last week" is a bit ambiguous, use "last 7 days"
Set no-cache headers on /cover-art-upload response