Merged ipv6In and ipv6Out gates into ipIn and ipOut.

There are network layers for ipv4, ipv6, generic network protocols.
Multi network layer is also available.
Renamed functions to be more consistent with others.
Added GenericNetworkConfigurator to configure GenericRoutingTables with static routes.
Fixed compilation when all features are turned off.
Added features for new routing protocols.
Renamed *AddressPolicy to *AddressType.
Comments.