MFC 256657,257423,264837,267559:
Sync vmrun.sh with HEAD:
- Add -e option to vmrun.sh passed to bhyveload(8) to set loader
  environment variables.
- Stop passing unused -I option to bhyve(8).
- Reformat the usage to fit in 80 colums and other cleanups.
- Add -C option to specify the console device.
- Add -H option to pass a host path to bhyveload(8).
- Support for multiple disk and tap devices.
MFC: r268115
Merge the NFSv4.1 server code in projects/nfsv4.1-server over
into head. The code is not believed to have any effect
on the semantics of non-NFSv4.1 server behaviour.
It is a rather large merge, but I am hoping that there will
not be any regressions for the NFS server.
MFC r266902: Add missing libexec/bsdconfig subdirectories