[boost] [assign] comitted some fixes for array test (this is a call to Thorsten)

I've just commited a couple of trivial fixes so that the test assign does now work for toolset msvc (and possibly for msvc-stlport and intel- win32-7.1-vc6, too.) Thorsten, are you there? I'm afraid he's on vacation or something. If he does not appear and nobody complains, I'll try to clear out more problems in the Assignment Library next Monday. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo