Implement first draft of PingPongService and Host

* Implement first draft of the PingPongService (with Ball_In and
Ball_Out)
* Implement the self-hosting in the WSPingPongHost project (incl. MEX)
add folder structure for C# and Java projects
Merge pull request #5 from devinmotion/master

Implement first draft of self-hosted C# PingPongService