KVM SR: update pinned egg versions.
KVM SR: export: use new slapos.toolbox qemu qmp wrapper.
KVM SR: resilient: add backend_url promise.

It will force the connection parameters to bubble up to reach the user.
Resilient stack: add promise for ssh key presence of PBS in root instanec.
KVM SR: resilience test: update md5 of disk image.
KVM SR: update egg versions.