Don't treat inner classes as test classes with ant.

Don't treat inner classes as test classes with ant.

This had been causing errors like

    [junit] Testsuite: nom.tam.util.test.ArrayFuncsTest$CloneTest
    [junit] Tests run: 2, Failures: 0, Errors: 2, Time elapsed: 0.039 sec
    [junit]
    [junit] Testcase: initializationError(nom.tam.util.test.ArrayFuncsTest$CloneTest):  Caused an ERROR
    [junit] Test class should have exactly one public zero-argument constructor
    [junit] java.lang.Exception: Test class should have exactly one public zero-argument constructor
    [junit]     at java.lang.reflect.Constructor.newInstance(Constructor.java:532)

The fix follows a patch submitted by peter to the hamake project [1].

[1]: http://code.google.com/p/hamake/issues/detail?id=55