Abstract transport layer

[sfertman]

Right now there is only http. To add a bunch more, I'll need to abstract send-message function so that it works with ws, tcp, udp and whatever else the kids say is cool these days. Make it like a plugin system.

Maybe even put client and server code in the same file. We can afford to be a bit fatter to gain simplicity.

[sfertman]

Now that I have another transport, this should be next on the agenda