444517 - Ensure WebSocketUpgradeFilter is always first in filter chain

  * Using Servlet 3.1's ServletContext.addFilter() mechanisms with its
    FilterRegistration to encourage the WebSocketUpgradeFilter to be
    first in the filter chain.
    Note: this is possible, but can be overridden by another call
    to the same ServletContext.addFilter() using the same techniques
    to put something in front of the WebSocketUpgradeFilter.