Add headers to allow use with project-fifo
add section about project-fifo
Merge branch 'master' of github.com:johnko/smartos-image-server

# By John Ko (3) and johnko (3)
# Via John Ko (4) and others
* 'master' of github.com:johnko/smartos-image-server:
  undo revert
  add section about project-fifo
  Add headers to allow use with project-fifo
  Revert "send content length when serving files"
  Revert "too many groups, only take first??"
  too many groups, only take first??