Re: [libvirt] [PATCH v4 5/8] Qemu arbitrary monitor commands.

Implement the qemu driver's virDomainQemuMonitorCommand and hook it into the API entry point.

Changes since v3: - Add a flag to priv so we only print out monitor command warning once. Note that this has not been plumbed into qemuDomainObjPrivateXMLFormat or qemuDomainObjPrivateXMLParse, which means that if you run a monitor command, restart libvirtd, and then run another monitor command, you may get an an erroneous VIR_INFO. It's a pretty minor matter, and I didn't think it warranted the additional code. - Add BeginJob/EndJob calls around EnterMonitor/ExitMonitor