[DaveBlake]

I have been so busy since April  I didn't have time to tell anyone what I was doing!! Here is a catch up of the major improvements and new features:
 

1. Liberation of local art types supported
   Make automatic fetching of any type of local artist and album art configurable (rather than hard coded) via a white list of art types (matching filename)  PR13848. Skinners and art fetching addon authors need to work together as a community to decide what common art types they will support, but this no longer needs any core changes to Kodi itself. For v18 this is an expert user feature rather than something I expect every user to master, but I hope configuration will eventually become part of skin/addon setup.
   
   
2. Media Source as Filter for AArtists, Albums and Songs
   Add music library facility to filter artists, albums and songs by media source. PR14012. This is something for users, especially those with large and diverse music collections (like mine).
   
   It is very natural to categorise music by putting it under separate folders, and in v18 with the introduction of the Artist Information Folder, users can arrange their music files into whatever folders they like (there is no longer any need to try to have all the music by an artist, and only that artist, under one unique folder in order to have local art and artist.nfo files). So say you arrange your music into folders they like e.g. "Opera", "Kids stuff", "Party Music", "Top Jazz Music", "Why did I buy this" etc. , then by simply adding these as separate sources (via the media source dialog), filtering based on source is available from the side blade filter and smart playlist/custom node rules.
   
   
3. JSON API Music Data Faster Access
   An internal reworking of the batch access to song, album and artist data via JSON API has made it significantly faster (~ 5 times depending on the data requested). PR14160 This makes apps such as Yatse and Kore, that fetch music data in batches, much faster to sync.
   

See pull requests for more details. I also fixed some bugs along the way - a devs work is never done.