This all either have been migrated to core3, or is not needed anymore.
There is still qvm-tools directory with a few tools that needs to be
migrated, or installed as is.
This way it will work independently from where qrexec-policy tool will
be called (in most cases - from a system service, as root).
This is also very similar architecture to what we'll need when moving to
GUI domain - there GUI part will also be separated from policy
evaluation logic.
QubesOS/qubes-issues#910
