Stable Release 10.6.0

[randomnicode]

There seem to be enough changes and stability now to merit a stable release.

Thereafter we can move to 11.0 snapshots and merge breaking changes to upgrade old stuff to modern counterparts.

If there are no outstanding bugs/issues in the next few days for the current prerelease, it'll get promoted to stable.

[randomnicode]

Last call for issues stopping stable release.

Next release WILL be breaking and NON-backwards-compatible!!

[chrstn-hntschl]

When trying to switch from vanilla airsonic to this implementation I realized that the mobile app I am currently using (DSub, https://github.com/daneren2005/Subsonic) fails to connect to the server, most likely due to the changes in credentials management. Are you aware of mobile applications (android) that work with airsonic-advanced?