Log Message:
* Add a MESSAGE file with helpful information for NetBSD domain0
  installations.

* Modify the package to not install all of the configuration files with
  the execute bit set -- only install the helper scripts that way.

* Update the block-file-nbsd script to not blindly try to configure (and
  often fail to configure) every vnd(4) device until it finds one that
  works.  We now just determine what the next free vnd(4) device is and
  configure it directly.

* Add a netbsd-nbsd script that avoids trying to do all the Linux-specific
  that just filled the log files with garbage on NetBSD.

* Update the vif-bridge-nbsd script to check that the bridge device is
  configured before using it.

* Add clear comments at the top of scripts that can be customized so that
  the user has enough information to know how to do the customization.

* Add a xendomains rc.d script that can be used to start and stop guest
  domains at system boot- or shutdown-time.

Bump the PKGREVISION to 5.