Add unit test for hostdev common library. Current tests are based on virpcimock.

Mark many parameters as NONNULL and check for empty list of
hostdevs.

Changes parameter from vm def to specific hostdevs info and name info, so that
it could be used more widely, e.g, could be used without full vm def info.

Change any variable names with Usb, Pci or Scsi to use
USB, PCI and SCSI since they are abbreviations.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Some virHostdevXXXX methods included the string Hostdev again
as a suffix. Change the latter to Device instead.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Change any method names with Usb, Pci or Scsi to use
USB, PCI and SCSI since they are abbreviations.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Various methods in virnetdev.c and virhostdev.c were missing
const-ness for several char * parameters.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Extract general code from qemuDomainReAttachHostScsiDevices to
virHostdevDomainReAttachHostScsiDevices.

Extract general code from qemuDomainReAttachHostUsbDevices to
virHostdevDomainReAttachHostUsbDevices.

Extract general code from qemuPrepareHostSCSIDevices to
virHostdevPrepareHostSCSIDevices.

Extract general code from qemuPrepareHostUSBDevices to
virHostdevPrepareHostUSBDevices.

Extract general code from qemuUpdateActiveScsiHostdevs to
virHostdevUpdateActiveScsiHostdevs

Extract general code from qemuUpdateActiveUsbHostdevs to
virHostdevUpdateActiveUsbHostdevs.

Extract general code from qemuUpdateActivePciHostdevs to
virHostdevUpdateActivePciHostdevs.

Signed-off-by: NChunyan Liu <cyliu@suse.com>

Only wait for kvm device cleanup if the driver is pci-stub