Fix multiple problems in multihost migration test server part

@lmr I don't know why are removed your and ypu commits da2292c b1d7886 f911b90.
But without ypu commit it will not work:-)

***require*** https://github.com/autotest/tp-qemu/pull/125

This pull req solve:
* client dns name problem
* moves configuration to server part of configuration
* fix path of results
     ``` resultsxxx\multitost-mitraiton\results\subtestsname\(dns|ip)name\results ```
* solve basic boot strap of qemu virt tests 
Tested with this modification and get this error:
 AttributeError: 'module' object has no attribute 'resultsdir'

So maybe we should use self.resultsdir here?

And can use switch the host.host.hostname and host.params["shortname"] so the results structure will still the same as before.