Merge from trunk:
* bad_any_cast exception is now visible across modules (fixes #8751)
* portion of optimizations and tests for rvalues
* added ability to call any_cast<T&&> (which is equivalent to std::move(any_cast<T&>))
* added clear() member function
* added missing BOOST_NOEXCEPT

[SVN r85151]
Merge tests of Boost.Any from trunk (refs #6999)

[SVN r85511]
Merge from trunk:
* Fixed construction of `any` from `const any&&` (fixes #9215)

[SVN r86298]