[boost] Boost Exception integrated with throw_exception.hpp

I've committed the change to throw_exception.hpp which enables the support for exception_ptr and other Boost Exception features for all exceptions emitted from boost::throw_exception(). Boost Exception has been tested on a variety of platforms and compilers, but the throw_exception() function is used by many different Boost libraries, some of which work even on compilers that are not officially supported by Boost today; so the new throw_exception() behavior can be disabled using #define BOOST_EXCEPTION_DISABLE. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode