Even more cleanup of the server

I have started to move things out from the massive OTServer.cpp file. Splitting things on a high level so that we see what kind of things it is dealing with in order to get things under control.

Let's aim for a single responsibility and well scoped classes that tell us what they are for!

Also we need to layer things in a way that there is a foundation and on top of that we have the server "runtime". I.e. get some classes that process/manage/handle transactions and such and then wrap that in a communicating server.