renamed plugins to contrib (they are not really plugins)
rewrote README.md to reflect new usage
added new dir to setup.py so it gets copied with installation, in views
of making using inventory scripts easier in teh future
Current code has sys.exit(1) at the end of the codepath for the
options --help, --list and --host. These are not error conditions
so should be returning 0 for success, not 1 which is EPERM i.e.
"Operation not permitted". Newer Vagrant versions examine the exit
codes from subprocesses and interpret this as a failure.