virt: multi_host Use enhancement in new cart config.

Signed-off-by: Jiří Župka <jzupka@redhat.com>
virt: Fix bug in migration for spice protocol.

Signed-off-by: Jiří Župka <jzupka@redhat.com>
virt: Some fix steps and multi_host migration.

steps:
  allow start steps test with other VM than main_vm.

multi_host migration:
  makes timeouts little longer due to slow win tests.
  add options to skip logging to vm.

Signed-off-by: Jiří Župka <jzupka@redhat.com>
virt: Expands multihost migration test.

Allow test start pre_sub_test before migration.

Signed-off-by: Jiří Župka <jzupka@redhat.com>
virt: Adds multihost test migration with GPU in VGA mode.

Guest has to be prepared for running with qlx
driver. Drivers have to be properly installed
before starting of the test. Otherwise the test
could FAIL.
tests steps:
    1) starts windows XP guest on first host
    2) try login to guest
    3) starts presubtest steps with
       stepsfile = WinXP-set-VGA-mode.steps
       enable VGA mode on GPU
    4) after presubtest finished starts migration
       to host2
    5) after migration starts postsubtests with
       stepfile = WinXP-reset-VGA-mode.steps

Signed-off-by: Jiří Župka <jzupka@redhat.com>