Added WebSocketFactory as alternative to deriving from NanoWebSocketServer
moved code from NanoWebSocketServer to WebSocketResponseHandler, so that requests can be handled without the presence of NanoHTTPD
Added basic test for websockets
Simplified the test using Mockito, and expanded what was being tested along with some other minor cleanup
expanded plugins to also recieve IHTTPSession so it has more access to
the request's state. Gives plugins access to Method, HTTP Headers,
Parameters, and the raw Input Stream
Fixed plugin argument signature for markdown plugin