Recv

Receive working on the GUI. Issue was C# was garbage collecting the receive callback and storing that as a member variable of Ddom resolved the issue. I also had to integrate events in the ddom.dll to fix some C function pointer issues as well.

There are some limitations here, one, we couldn't create threads in a marshalled thread, so the current display of messages in the gui doesn't work. It will probably need something like how the invite thread works. Fixed in new commit To see that receive works, there is a debug statement that does show that messages are being received and it writes to the logfile.