* qemud/conf.[ch]: significantly re-factor qemudLoadConfigXML()
        so that "parse the XML", "assign the def to a VM" and
        "save the XML" operations are in separate functions.
        Add qemudRemoveInactiveVM() and qemudRemoveInactiveNetwork().
        Report errors when loading config files at startup. Check
        that a domain/network's name matches the config filename.

        * qemud/driver.c: update the Create() and Define() functions
        to explicitly parse/assign/save. Also, fix bug where if
        Create() failed, we would free the VM without removing it
        from the inactive list.

        * qemud/qemud.c: use qemudRemoveInactiveVM/Network()