Fix archivers test suite broken by transition to Catch

The code of ziptest and tartest classes still compiled, but actually
didn't do anything during the run-time because makeSuite() method was
never called.

Replace this unused method with DoRunTest() and override runTest() in
the test suite classes to actually run the tests.

tests/archive/archivetest.h

@@ -249,7 +249,7 @@ public:
     ArchiveTestSuite(std::string name);
 
 protected:
-    virtual ArchiveTestSuite *makeSuite();
+    void DoRunTest();
 
     virtual CppUnit::Test *makeTest(std::string descr,
                                     int options,