Relay prototype

Considering getting this simple relay implementation into ThaliProject while I finish up the other aspects of it - to simplify folks using the HTML5 seed.   Perhaps into a new branch on ThaliProject - but then you wouldn't be able to see the diff for review.

Only one source file here for the relay - RelayWebServer.java (and RelayWebServerTest.java).  The other bits are all NanoHTTPD.  Open questions on code file headers for those....
Please file a bug that the port needs to eventually be made dynamic. Otherwise we literally can't run two apps at the same time. This IS NOT a show stopper right now. I just want to make sure we have the bug so we don't forget.