MOF14 — resolveQualifiedName operation

I think it would be much more convenient to have resolveQualifiedName as a
"classifier_level" operation on ModelElement instead of "instance_level"
operation on Namespace. Now each time I want to resolve some object using
its qualified name, I have to find all outermost packages (which is quite
slow, because currently there is no better way of doing it than just iterate
through all package instances and check whether they are outermost), then
choose a package with a specified name and call resolveQualifiedName on that
package passing rest of the qualified name as a parameter. This is much more
complicated for users than it should be.