NetReload: Move removeBondings and editBondings implementation to ifcfg.py

Change-Id: I224512bd719f43f77389a503e81a36734670dbd9
Signed-off-by: Mark Wu <wudxw@linux.vnet.ibm.com>
Reviewed-on: http://gerrit.ovirt.org/14198
Tested-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>