Ilsgateway integration

@czue I moved changes from ilsgateway-products-integration to this branch and I added webusers integration. I will be pushing all integrations with ilsgateway in this branch.  Is it ok? I assume that you don't want to merge this changes until it will be completely done?
@czue @kkrampa But if you had the ILSGateway handler just return False (so that it passes the message onto other handlers) any time you'd need the CommTrack handler to also process it, wouldn't you have the same behavior as the signal is providing?