Encode Bignums using the smallest possible representation
Encode Bignums using the smallest possible representation

This is how the MRI implementation handles Bignums.
ojundt/msgpack-ruby,msgpack/msgpack-ruby,cosmo0920/msgpack-ruby,msgpack/msgpack-ruby,msgpack/msgpack-ruby,cosmo0920/msgpack-ruby,ojundt/msgpack-ruby,cosmo0920/msgpack-ruby,cosmo0920/msgpack-ruby,ojundt/msgpack-ruby,ojundt/msgpack-ruby