Move articles to the front of Discogs artist names.
Move match distance weights to an undocumented configuration setting.
Rename the `discogs` max rec setting to `non_mb_source`, so it can apply to all data source plugins.
Check for both track length and number difference independently when downgrading recommendations.
Update examples in docs to reflect new UI enhancements.
Add Discogs and general source weight penalty (configurable, undocumented).

Discogs (and other individual plugins) should return a penalty between
0.0 and 0.1, which will be multiplied by the general source weight. This
allows individual plugins to be weighted against relative to each other,
and amplified together against other penalty categories (track, title,
etc.)
Add missing import.
Fixes a bug when trying to modify the artpath with special characters

Basically, it uses the helpers that handle conversion bytestring <-> unicode with the item's path, but weren't being used with artpath. For now, it just fixes the behavior for `modify`