Provide a Portals Bridges common.PortletResourceURLFactory implementation for Jetspeed

Portals Bridges now provides a PortletResourceURLFactory interface, see PB-65, which is defined for creating direct Portlet access urls, somewhat similar to what the Portlet API 2.0 ResourceURL will bring natively.

For Jetspeed-2 it will be quite easy to provide an implementation of this interface by serving a (Render) request over the portlet-pipeline.
The only requirement will be that the portlet-pipeline is defined (under that name) in the Spring assembly as it will be invoked using a PortalReservedParameters.PIPELINE request parameter.

One caveat: By default (although configurable) Jetspeed-2 stores navigational state in the session, so parameters set on the RenderURL as created by our PortletResourceURLFactory implementation might be saved too. But that is not what should happen as these ResourceUrls should not change the nav-state.
So, I'll define additional reserved (portal) request parameters to indicate the provided request nav-state is to be treated as transient.