since there are certain things, such as schemaLocation attributes, that have a...

since there are certain things, such as schemaLocation attributes, that have a datatype and which we nonetheless do not validate, make canonical-value production dependent on validity being valid


git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@175516 13f79535-47bb-0310-9956-ffa450edef68