Bug 515476: Don't assume schema location for Web App projects

Fixes JavaEEQuickpeek.getVersion() so that the schema location of a
deployment descriptor does not need to be specified. So long as we know
the namespace and schema type, we can determine the version.

Also-by: Brian de Alwis <bsd@mt.ca>
Signed-off-by: John Collier <John.J.Collier@ibm.com>