v0.6.0-beta

• mscgen compatibility:
  • allow attributes without quotes (mscgen allows this implicitly, though currently not present in one of its testcaes)
  • make self ref line colors work
• nicer dot output (still behind "debug" fence)
• favicon(s) (we're using the Chinese character 序 ('xù') which means something like 'sequence' or 'order')
• code stuff (shifted some code 'round, simplified some things, added some scripts for juggling favicons, made pngs smaller with optipng)