Created attachment 24258 [details]
When the Context is stopped, clears the listeners list

When a WebApp is refreshed, the following warning is displayed:

"StandardContext.addApplicationListener : The listener
"com.sun.faces.config.ConfigureListener" is already configured for this
context. The duplicate definition has been ignored."

This is because the TldConfig instance does not react to a STOP event of the
StandardContext. It should clear the list's content when the WebApp is stopped.

We've encountered this bug with tomcat 6.0.20.
I've checked the Tomcat7 TldConfig code to see if the issue may still be there,
but I'm not sure: there is some code dealing with already registered taglib URI
that may prevent the warning.

So the provided patch is against tomcat6.0.x branch (but should be easy to port
to trunk if there is some interest).

BTW, I've checked the TldLocationsCache source code, but it is not implementing
the LifecycleListener interface, so that patch cannot be applied on that file
...