LAG logical port update - 2

Added changes in lag module for handling the #lag #aggregator #logical #interface #status #change s. Similar status handler has been added for #lag #member #port s as well. When member port status is changed in other modules (e.g. ethernet) it will cascaded to lag module. The member port status changes may cause aggregator port status change as well. This will enable lag module to perform aggregator specific operations to be performed on relation with the member port status change.

#LAG update 9 ...
[commit 58cf74e3070a523621f97d5b1a0ad465fcedc08b]