types: Tuple name and id when passing to service

Minus one method for type classes.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
phaul: Copy htype's meta images when sending them to target

Some stuff can be carried with the CRIU's state during
migration, e.g. config files.

In case of ovz type -- it _is_ the config file.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
htype: Notify scripts that restore is complete

In Ovz driver -- write a pidfile with real pid of
the restored task.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>