update port_index() for loopbacks
add get_bondmems() function to bond_iface.py
bondmem_iface - create print_bond_state func
change the way vlans are printed using the new bridge driver.
before iface.vlans['tagged'] = [1,2,3,4] now its
iface.vlans['tagged'] = {'vlan1': '1', 'vlan2': '2'.... }
The reason for this change is to provide consistency between the way vlans look
in classic bridge driver mode and new bridgedriver mode.
add way to check if link is adm down.