Broaden Java-side test coverage to compile everything under `test/src'.
Tests are still explicitly chosen via the nested <arg> to the '//abcl.test.java/java@' element at build.xml:940 ff. The test in org.armedbear.lisp.util.HttpHeadTest currently hangs (!) the executing VM, a high priority item for abcl-1.3.0. The problem lies in a hanging read in the JVM system classes that previously didn't exist when accessing the ZipCache.get(url) API for the second time. Users are advised to call SYSTEM:DISABLE-ZIP-CACHE until this behavior is fixed.