RFR 8156825: java/net/httpclient/BasicWebSocketAPITest.java failed with "java.lang.AssertionError"

[Michael McMahon]

Could I get the following change reviewed please? There are three small 
changes

1) enhancements to RawChannel API used by websocket implementation
2) fix the test case problem where channel might not be in non-blocking mode
    (also remove erroneous asssertion check)

3) Remove (unused) and unintentionally public HttpHeaders1 type

http://cr.openjdk.java.net/~michaelm/8156825/webrev.1/

Thanks,
Michael