Sheepdog: cold migration and caching
ITECO: cold migration: shared_storage and destination host
ITECO: Do not create base vdi if target vdi exists
ITECO: -t directsync for qemu-img sheepdog write
Sheepdog cache: fix locks
Cold migration: target host and shared storage fix
Fix destroy instance on shared storage, add soft reboot
Merge branch 'sheepdog_cache' into iteco

Conflicts:
	nova/virt/libvirt/imagebackend.py
Merge branch 'iteco' of https://github.com/maelnor/nova into iteco