Ability to use SERVICE_x_NETWORK

[joatmon08]

trafficstars

Based on #498, allows specification of the Docker network for the specific service and port if -internal configuration is set. This is similar to #316 but allows individual services to specify which network they must use rather than default to one network (for example, in environments where services are mixed on bridge and overlay). Service uses SERVICE_x_NETWORK or SERVICE_NETWORK to choose the network.

[logankoester]

Yes please!

[akamac]

Can this be merged please? Right now there is no way to pick the correct network/interface for the service being registered, when the container is attached to multiple networks.

[anhgien]

Please merge this pull request guys!