Make columns of equal sizes at first start
Merge pull request #353 from zas/metadatabox_sizes_2

Metadata box: make columns of equal sizes at first start
Display a simple dialog to select cover art types

It is much more convenient than the list widget.
The dialog includes "Check All" and "Uncheck All" buttons, as well a "Help" button.
Add option to disable all restrictions to CAA types

This is better since the list of types may change, adding a "do not restrict" ensure
all types are downloaded if more types are added to MB.

If restriction is enabled, then previous behavior is used (downloading only images having specified types).
Merge pull request #352 from zas/caa_types_dialog

Display a simple dialog to select cover art types
PICARD-631: honour preferred release formats when matching AcoustIds

`format` wasn't copied to rebuild xml node during acoustid matching
Merge pull request #354 from zas/PICARD-631

PICARD-631: honour preferred release formats when matching AcoustIds
Update pot file
Update MB_ATTRIBUTES: CDV format added

Updated using `python setup.py update_constants`
Update .po files
Update po files
Update .po files
Update links to use new Picard website (http://picard.musicbrainz.org)
Display main libs versions in debug log

We were already displaying pyqt, mutagen and discid versions in About dialog, now they'll be shown in debug log too.
It will help with debug logs provided by users.
Merge pull request #357 from zas/versions

Display main libs versions in debug log
Merge pull request #356 from zas/new_links

Update links to use new Picard website (http://picard.musicbrainz.org)
Convert xml nodes values from str to unicode
PICARD-633: fix up artist's name translations

See http://chatlogs.musicbrainz.org/musicbrainz-devel/2014/2014-09/2014-09-18.html#T20-39-39-835764

Scores help when it comes to ambiguous choices, see tests.
Add dev utility function printable_node()
Update picard.pot