Create test ODD that gives classRef a workout

[hcayless]

I'm not confident that the attributes which can be used to modify <classRef>, namely @expand, @include, and @except have been implemented. We need an ODD + test that exercises these.

See TEIC/TEI#1412

[lb42]

Added testClass.odd to Stylesheets/Test : the good news is that almost everything appearently works as it should when generating Relax or XSD: there is one minor glitch (test7a) Predictably the DTD generated is rubbish, of course.

[lb42]

(I havent added anything to the Makefile to ensure that this new test file gets exercised during the build though, nor have I added a test XML file; pending review)

[JanelleJenstad]

Assigning to @HelenaSabel because this ticket is the test for the #139