HP ProCurve LAG support by inheriting Info::Aggregate class
Cisco PAgP support added to LAG method

Squashed commit of the following:

commit 5cb2d637c7e990bbb8f789b6878f4bcb99778157
Author: Brian De Wolf <git@bldewolf.com>
Date:   Wed Feb 26 18:31:22 2014 -0800

    Implement agg_ports_pagp

    This function was a stub that is now filled out.  Also filled out the function
    that merges PAgP and LAG groups and did minimal testing of the PAgP side (no
    LAG in use in my env).
release 3.13
make addr_prefix work for vrf on IOS 15.2.x
c4900m needs vtp extensions on ios 15.2.x
nexus 6.2 needs ifPhysAddress.83886080 instead of dot1dBaseBridgeAddress