Added tagged exception info map. Added fl_throw macro. Implemented static Exception::throw_exception taking rvalue and lvalue ref and non-ref exceptions. Replaced boost::lexical_cast with std::to_string.
Added tagged exception info map. Added fl_throw macro. Implemented static Exception::throw_exception taking rvalue and lvalue ref and non-ref exceptions. Replaced boost::lexical_cast with std::to_string.

filtering-library/fl,SimonEbner/fl