Added 'distclean' target and clean up test output in 'clean' target.

Makefile

@@ -223,6 +223,13 @@ $(BUILD)/fuzz: $(PROG_OBJS) $(DRIVER_OBJS) $(BUILD)/fuzz.o
 
 clean:
 	rm -rf build/* build_arm/* build_debug/* build_arm_debug/* *~
+	$(RM) testaes/test_input.txt testaes/test_stderr.txt
+	$(RM) testoutput/test_expected.txt testoutput/test_input.txt \
+          testoutput/test_response.txt testoutput/test_responses.txt \
+          testoutput/test_stderr.txt
+
+distclean: clean
+	$(RM) config.log
 
 clean_cc:
 	find . -name "*.gcov" -delete