Limit a music track to several sides or to an expansion

NewPlanned for 0.2.0

A music track’s Side= now takes a list of sides, and the new RequiredAddon= keeps a track out of the playlist unless that expansion is running.

CCHyper is credited for the Vinifera RequiredAddon=, which checks whether the expansion is installed rather than running.

Affected entities

Credit: ZivDero, CCHyper