JAVA-1391: Javadoc for AsyncCompletionHandler
JAVA-1391: Javadoc for NativeAuthenticationHelper
JAVA-1391: Javadoc for public classes that should not be considered part of the public API.
InternalStreamConnectionSpecification updates

The reading of headers now has the messageId explicitly set.
Update README.md

Updated Maintainers and added travis build icon
Fix explain tests for 2.7-nightly