for JAXRSClientFactory and WebClient
methods that allow user to pass in true for creating
thread safe proxies there is no way to pass in
long timeToKeepState to specify how long before cleaning up that state
to be passed down to ThreadLocalClientState constructor.
I've provided method to pass in timeToKeepState in both
JAXRSClientFactory and WebClient that allows user to pass timeToKeepState (note per Sergey's response in the user mailing lists only providing one more version to not clutter the factory with too many overloaded methods)