Fature request: Netwatch per interface

Some easy stuff to implement: Netwatch ping test should allow an “per interface” option, so that we can easily check whether a PPPoE or VPN connection is ok or not by pinging 8.8.8.8 on that very interface.

Such request was raised already.
http://forum.mikrotik.com/t/feature-request-netwatch-parameters-extension/75502/1