[libvirt] [PATCH] Libvirt Snapshot API

A little while ago I submitted a patch to add a snapshot API, but I was informed that it got somewhat lost in the list. I have attached a patch that implements this API at least for the qemu driver, and it also added another function for screenshots, just because it usually is nice to get a view of the screen with the snapshot. The snapshot functions just take names, as I figure it should be up to libvirt to figure out where the snapshots go. e.g. for qemu, they just get stored with the drive using qemu's built in facilities. If someone were using LVM, then that could be managed by libvirt, just like it does for qemu monitors and such. The 'list snapshots' just returns a list of names for now, as that's all I needed, but I think it would probably be best to add a struct that would be name/time. I don't know if it's of any use at the moment, but I needed these functions implemented, so I figured I'd at least submit my changes Philip Jameson