#4 generalize RouteTable propagation rules

[Misterblue]

At the moment, event filtering and lease propagation is
controlled by TYPE_CLIENT and TYPE_PEER flags in the RT
entry and the Outter's parent getConnectionType(). The
route table should have the type field removed (and
have the destination Outter's check to make sure they
accept the event) and have an optional class that will
test to see whether the lease should propagate.
getClientChannels() could get a 'context' parameter and
the called method would get context and the event to
decide on lease forwarding questions