- Fix build error and other improvements.
- Fix build error and other improvements.

- Cleaned up the confusion with SUBSONIC_BIN, SUBSONIC_DATA and
  SUBSONIC_HOME. SUBSONIC_HOME now points to the state directory
  by default (/var/subsonic). This is an unfortunate name but is
  also the name used in the upstream subsonic.sh file.
- SUBSONIC_BIN is now the home directory for the subsonic user
  inside the container and the location for the downloaded subsonic
  binaries.

marcopaganini/alpine-subsonic