Add cleanup function for packer

This also removes the ugly reboot in _lib/install.sh
Treat vagrant as a special user with static passw
add CLEANUP var to point to post/packer
add packer cleanup script
set branch to vagrant
corret url to branch
rename cleanup to cleanupChroot
added post_chroot to handle end of install
Renamed cleanup to cleanupChroot
change name for CLEANUP var
update post/packer.sh