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....
Yeah, I'm looking at switching over to that, or at least adding new tests that way.  My asserts are regex based and I've used wildcards in appropriate spots, but I can increase the wildcards there.

My problem is that we need to test headers primarily, and a contains check doesn't catch many problems (like duplicate headers, or extra headers).  

Either via moving to that model or a hybrid where I've substantially wild carded the line-by-line checks I'll make sure its more maintainable.