Add headless option into wrapacker script
Add headless option into wrapacker script

Only works with virtualbox provider.

agt-the-walker/packer-arch,slash170/packer-arch,aidanharris/packer-arch,cosmo0920/packer-arch,elasticdog/packer-arch,appleby/Lisp-In-Small-Pieces-VM,tomaspapan/packer-arch