[boost] [swap] unbreak tests

I've checked in the below. The libs/utility/swap/Jamfile.v2 has the same content present twice (complete with copyright notices). This is not good, because if you ask Boost.Build to built two targets with the same name, the same set of sources, and otherwise identical, Boost.Build asks "wazzup?". I suspect this duplicate content is a consequence of how the "patch" program handles file addition, but anyway, it's nice idea to actually run library's test before touching the library. - Volodya