schema 1.1 commit: committing a minor improvement to assertions implementation. this handles better the case, when assertions are within a simpleType->union scenario (particularly, when a memberType of union in non XSD namespace having non-assertion facets can validate successfully an XML instance value).

git-svn-id: https://svn.apache.org/repos/asf/xerces/java/branches/xml-schema-1.1-dev@1429469 13f79535-47bb-0310-9956-ffa450edef68