Updated to Jersey 2.0-m12-1 which implements JAX-RS 2 m16 API. Refactored the code to compile with this version.

Updated to use Jetty 9.0.0-RC1 snapshot repository, to use OutputStream Content Provider support for async requests (https://bugs.eclipse.org/bugs/show_bug.cgi?id=400434)

Using Jetty InputStreamResponseListener to stream response from async request. Some minor code cleanup when building the async request.