KVM/QEmu migration support

KVM/QEmu migration support
* qemud/remote.c qemud/remote_dispatch_localvars.h
  qemud/remote_dispatch_proc_switch.h qemud/remote_dispatch_prototypes.h
  qemud/remote_protocol.c qemud/remote_protocol.h
  qemud/remote_protocol.x src/driver.h src/libvirt.c
  src/libvirt_internal.h src/libvirt_sym.version src/lxc_driver.c
  src/openvz_driver.c src/qemu_conf.h src/qemu_driver.c
  src/remote_internal.c src/test.c src/virsh.c: large patch to
  add migration support for KVM/QEmu, based on the work of Rich Jones
  and Chris Lalancette. This introduce a new version of the prepare
  and finish steps of the migration, so changes the driver API and
  a lot of code.
Daniel