Brigadier 0.2.1

• '--model' option can now be given multiple times to do multiple downloads
  in a single run
• update dmg2iso to 1.6.5
• update 7-Zip to 9.34 alpha
• update default SUS catalog to the Apple 10.9 catalog
• '-l/--leave-files' is now '-k/--keep-files', following the naming pattern
  most other utilities use when keeping files around.
• fix issue where the supported models list reported when multiple matching ESDs
  were found was inaccurate
• fix issue where 7-Zip would fail to find a 'Payload' archive; certain ESD DMGs
  recently expose only a 'Payload~' archive to 7-Zip, so we no longer assume
  both exist