tlbBuilder: resulting tlb-file for classes.h

stupid cmake... because of using "glob" to find the headers, adding a new
test-header is not noticed by an existing build-folder-structure. so get
the target create-test-classes.tlb from the new classes.h the build-folder
has to be regenerated?

Signed-off-by: Martin Zenzes <martin.zenzes@dfki.de>