Moving HttpTester to "tests" scoped jetty-http artifact.

 + HttpTester, a testing class, was used by jetty-servlets,
   embedded-jetty-examples, and test-integration, all from
   those testing scopes.  Moved the HttpTester into the
   pre-existing jetty-http "tests" classified artifact.
Improved exception reporting.
440729 - SSL requests often fail with EOFException or IllegalStateException.

Fixed IllegalStateException by handling NEED_UNWRAP for the CLOSED
state in fill().
The EOFException does not seem to be an issue with the client.

Also removed an unneeded catch block and an empty if statement.