Add line continuation so OPENSTACKCONF is actually included
in the env(1).

Sponsored by:	The FreeBSD Foundation
Add a 'vm-cloudware' target, used to drive all
targets in CLOUDTARGETS.

Sponsored by:	The FreeBSD Foundation
Add examples for WITH_CLOUDWARE to release.conf.sample.
Add WITH_CLOUDWARE evaluation to RELEASE_RMAKEFLAGS.

Sponsored by:	The FreeBSD Foundation
Initial rewrite to consolidate VM image build scripts into one.
There may be some very sharp edges here while refactoring.

 - Move amd64/mk-vmimage.sh -> scripts/mk-vmimage.sh.
 - Remove vm-base target from Makefile.vm.
 - In vm-image target, use getopts flags for argument passing.
 - Create tools/vmimage.subr, containing default and prototype
   for the following functions that are used to drive the build,
   run in this order:

   vm_install_base()
   vm_extra_install_base()
   vm_extra_install_packages()
   vm_extra_install_ports()
   vm_extra_enable_services()
   vm_extra_pre_umount()
   vm_create_disk()
   vm_extra_create_disk()

 - In tools/azure.conf, override:

   vm_extra_install_base()
   vm_extra_pre_umount()
   vm_extra_create_disk()

 - In tools/openstack.conf, override:

   vm_extra_install_base()
   vm_extra_pre_umount()

Sponsored by:	The FreeBSD Foundation
Add write_partition_layout() used to populate the
final image.

Fix duplicated mkimg(1) call in vm_create_disk().

Add primitive (untested) PowerPC/PowerPC64 VM image
support.

Note: As it is currently written, the /boot/pmbr and
/boot/{gptboot,boot1.hfs} use the build host and not
the target build.  Fixing this is likely going to be
a hack in itself.

Sponsored by:	The FreeBSD Foundation
Return if vm_create_disk() is unsuccessful.

Sponsored by:	The FreeBSD Foundation
Add CLEANFILES entry for VM targets

Sponsored by:	The FreeBSD Foundation
Add vm_extra_pre_umount() prototype to vmimage.subr.

Sponsored by:	The FreeBSD Foundation
Fix DESTDIR for installworld, and make sure it is created
before use.

Sponsored by:	The FreeBSD Foundation
Move usage() from vmimage.subr to mk-vmimage.sh,
in case vmimage.subr has not been sourced.

Sponsored by:	The FreeBSD Foundation
Spell 'OPTARG' correctly.
Actually call vm_create_base().

Sponsored by:	The FreeBSD Foundation
Fix line continuation in write_partition_layout().
Remove variable test that is no longer needed.

Sponsored by:	The FreeBSD Foundation
Fix scheme flag to mkimg(1).

Sponsored by:	The FreeBSD Foundation
mount(8) and umount(8) devfs(5) as needed.

Sponsored by:	The FreeBSD Foundation
Change path for mk-vmimage.sh from ${TARGET}/ to
scripts/ now that it is consolidated into one file.

Fix paths for the base image and output disk image
files.

Sponsored by:	The FreeBSD Foundation
Call cleanup() after everything is done.

Sponsored by:	The FreeBSD Foundation