Working Linux build

[chadnickbok]

This is my first goal - to get this working successfully on Linux, including:

• Simple C wrapper
• Basic makefile
• Small example client that uses librtcdcpp and libwebsockets
• Small python example server that facilitates the simple client demo

[chadnickbok]

Initial CMakeLists.txt should now support linux

[mo3rfan]

I've written a C wrapper. It runs every peer connection in a child process and uses ZeroMQ's IPC in request-response pattern to communicate between parent and child. We needed this for our use case of having to create more than two peer connections within a single program. If you feel this is fine for your library, I can send a PR.