Adapt the tests to be invoked in one run. Note that multiple fake VMs
were used for the distinct tests so that they don't influence each
other.
This is the final coversion of tests to run in batch mode which halved
the runtime of 'virshtest' on my machine (1.11s vs 2.33s).
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>