utf-x sample unit tests should be executed as part of the regression test.
furthermore, all samples should be executed once for each XSLT processor
supported ; currently j2se5 buil in, xalan and saxon8
utf-x tests that are executed as part of the 'tests' target should also become
part of the regression test but this is little bit more tricky as for some tests
correct behaviour is to either fail or throw an exception. Some sort of a
wrapper test case would have to be written.