ServerContainer exposes WebSocketEngine
Adding WebSocketConnection class which represents a logical connection
established by a connector with tyrus.
Adding IncomingDataHandler class. A connector would use this class to
hand over the incoming data to tyrus.
TODO: need to work on names etc
Updating the spi (other modules do not compile yet)
Updating SPI
Added a comment
First take on adapting Grizzly Container to new SPI
Container SPI - compilable version
Container SPI - echo client works (hacky way)
Container SPI - EchoTest passes (hacky way)
Container SPI - All tests pass (hacky way)
Container SPI - more tests are passing (hacky way)
Container SPI - rebase github/master
Container SPI - whole build passes

- next: servlet, GF integration, autobahn test suite
Container SPI - Grizzly 2.3.5 -> 2.3.6
Container SPI - Servlet integration, autobahn tests passed
Container SPI - Grizzly container - server/client separation
Container SPI - Grizzly container improvements
Container SPI - Synchronous message sending improvements
Container SPI - removed Connection.open()
Container SPI - removed WebSocketEngine.webSocketHolderMap

- TODO: multiEcho test (related to sync messages processing)