v2.2.0 playlist timestamp release

This release features:

• NEW automated playlist timestamping #6
• NEW asset decoration to prevent stale CSS/JS assets in the browser cache
• Miscellaneous fixes:
  • extraneous backslashes in playlists #36
  • playlist formatting #30
  • listen-live link #27
  • library editor to scrub record label name #26
  • deprecated support for Netscape Navigator 4 (!!)

IMPORTANT NOTE: If upgrading from a previous release, you will need to run the script db/convert_v2_to_v2_2_0.sql.