NEEDS TESTING - rc script for bhyve

[Rudy (bulk)]

OK, I did test it a bit.  Really, I wanted something short to automate 
booting, but I ran into some issues that ballooned up the script.

Things I put into the script:
  0 - does no provisioning, I only want a start/stop script
  1 - adds vmtab for configuring VMs
  2 - supports grub loader
  3 - uses nmdm
  4 - runs VM with a heatbeat and automatically restarts unless the 
'stop' is run
  5 - 'stop' sends a graceful shutdown and the heartbeat loop doesn't 
restart as the pidfile is nuked
  6 - catches stalled bhyveloader and kills it


https://www.monkeybrains.net/support/bhyve.rc

Rudy