Since qubesd properly handle chained startup of sys-net->sys-firewall
etc, we don't need a separate service to start netvm explicitly earlier.
FixesQubesOS/qubes-issues#2533
This service currently does more harm (desync libvirt state with
reality) than good. Since we have qubesd, we may come back to
implementing it properly using libvirt events.
This is part of fixing qvm-start.
qmemman was moved with minimal touching, mainly module names.
Moved function parsing human-readable sizes from core2. This function is
wrong, because it treats k/M/G as 1024-based, but leave it for now.