The spec (javadoc) of ExceptionHandler.getRootCause() currently says the
following: "Unwrap the argument t until the unwrapping encounters an Object
whose getClass() is not equal to FacesException.class or
javax.el.ELException.class. If there is no root cause, null is returned."
I think instead of checking for equals() we should check for isAssignableFrom(),
because there are a lot of sub-classes (especially for ELException), which
should also be unwrapped.
See also the related MyFaces-issue at