Added generic match on SumTypes.
Removed accept(any, ...). Made use of using namespace std where possible.
Reorganized some file, and renamed any.hpp to match_any.hpp.
Don't introduce more symbols than needed in boost.
Added tagged wrapper type.
make tagged constructible from convertible to T.
Added tagged<T&, Tag> and tagged<T*, Tag> specializations.
Added int* and referencence_wrapper<int> match any tests.
Update doc with draft proposals for overload, match and tags.