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....
Somebody (probably me) is going to not like you in the future when even the smallest, tiniest change happens to the relay and all these tests break because the response is not character for character identical. I don't suppose you might, possibly, potentially, could, you know.... want to try something like https://code.google.com/p/rest-assured/?