This is to make sure that QubesVmCollection state is consistent with
qubes.xml - unfortunately some changes are applied to Qubes*Vm object
only at load time (for example connected_vms collections).
Test suite now logs to three places:
* syslog
* ${HOME}/qubes-tests.log
* /dev/kmsg (only start and errors; this is handy while debugging Oopses by
correlating them with tests)