Re: [boost] [type_triats] [move] is_copy_constructible<T> trait

I've added the trait and it passes all the regression tests. I've also updated the documentation.

Ion already merged the Boost.Move part to release so is_copy_constructible is ready for release.

John, take a look at it and if everything is OK with that trait, please merge it to release (or tell me, and I'll merge it). https://svn.boost.org/trac/boost/ticket/8802

Done. Many thanks! John.