Created abstract base classes for device and drivers, changed the flow of driver loading / device probing

Longer term it should be nice not to allocate the bars at all

host side reset calls

Added pci config capability parsing and moved the virtual call to earlyInitChecks() to the base class

We need only to store the virtual address returned from malloc.
virt_to_phys is the function translating the virtual mem into physical.

In addition, I founf a design error in the virtio PFN code. It will only
affect us on > 44 bit ram..

queue size correctly.

It was portion of BSD license and taken from Linux/uapi.
A matching license clause is under the license directory.