DatagramIterator: Fix get_<metadata>() and seek_payload() to use type-size constants.
DatagramIterator: Fix get_<metadata>() and seek_payload() to use type-size constants.

blindsighttf2/Astron,blindsighttf2/Astron,blindsighttf2/Astron,pizcogirl/Astron,ketoo/Astron,blindsighttf2/Astron,pizcogirl/Astron,pizcogirl/Astron,ketoo/Astron,pizcogirl/Astron,ketoo/Astron,ketoo/Astron