Type_traits: Added add_const/add_volatile/is_fucntion tests.

Updated docs for new templates.
              Updated test programs to test abstract base classes.


[SVN r9638]

examples/iter_swap_example.cpp

@@ -103,8 +103,7 @@ int main()
    opt::iter_swap(v1.begin(), v1.begin()+1);
    opt::iter_swap(v2.begin(), v2.begin()+1);
 
-   cout << "Press any key to exit...";
-   cin.get();
+   return 0;
 }