MFC r326068:
Remove /etc/resolv.conf from virtual machine images, which is
copied from the build host. It is renamed to /etc/resolv.conf.bak
on boot, so never used anyway.

Sponsored by: The FreeBSD Foundation

MFC r285722, r285733:

r285722 (brd):
Add support for building VirtualBox Vagrant images.
Abstract the build, package and upload to handle building
either type.

r285733
Fix an out-of-order execution issue regarding pkg(8):
- pkg(8) cannot be removed before subsequent reinvocations
- The PKG_CACHEDIR cannot be cleaned after the repo*.sqlite
has been removed
- pkg(8) cannot be removed as a precursor to any of the other
steps involved here

Approved by: re (kib)
Sponsored by: The FreeBSD Foundation

MFC r285722, r285733:

r285722 (brd):
Add support for building VirtualBox Vagrant images.
Abstract the build, package and upload to handle building
either type.

r285733
Fix an out-of-order execution issue regarding pkg(8):
- pkg(8) cannot be removed before subsequent reinvocations
- The PKG_CACHEDIR cannot be cleaned after the repo*.sqlite
has been removed
- pkg(8) cannot be removed as a precursor to any of the other
steps involved here

Approved by: re (kib)
Sponsored by: The FreeBSD Foundation