core: export & import highly available parameters

The 'auto startup' and 'priority' attributes of VM/Template were not
copied on export & import operations. Now they are.

Change-Id: I194b70181cf4ab0420044a22dd8a382766d9019d
Bug-Url: https://bugzilla.redhat.com/1057048
Signed-off-by: Arik Hadas <ahadas@redhat.com>