TYRUS-133: Optimized broadcast support.
TYRUS-133: ServletOutputStream synchronization
TYRUS-133: Modifications based on performance monitoring.

- testWebSocketBroadcast used for get the monitoring data
TYRUS-133: Added support for broadcasting binary messages.

- cleaned up tests, added docs, ...
TYRUS-133: javadoc adjustment
TYRUS-243: Added support for non-blocking connectToServer.

- see ClientManager#async* javadoc
- improved IOException reporting (was always wrapped by DeploymentException)
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