virsh_migrate_stress: SKIP test if src and dest URI not defined

Issue #1014.  Skip this test if we haven't redefined the source and
destination URI's.
Merge pull request #1239 from jferlan/virsh_migrate_stress

virsh_migrate_stress: SKIP test if src and dest URI not defined
 guest-os: add RHEL5.10 config

Signed-off-by: Shuping Cui <scui@redhat.com>
virsh_edit: Resolve random/obscure timing failure

Periodically I was getting a failure when the first of the sequence
of virsh_edit's are run in one my long runs using the "--tests virsh"
option. The failing test is/was 'virsh.edit.normal_test.id_option'.
When run alone using "--tests virsh.edit" - the error didn't occur.
After looking at the test for a while I noticed that part of the
processing is to shutdown the guest prior to the last modify_vcpu()
call. Doing that means the 'id' is no longer valid - thus a failure
could occur that wasn't expected. Even after changing that I got a few
more failures and after an attempt to change the sleep() time from 1 to 2
I was directed to the remote.handle_prompts() call which should work.
Merge pull request #1245 from spcui/add_rhel.5.10

 guest-os: add RHEL5.10 config