API is somewhat stolen from Rust std::fs::File. Static factories didn't work out so well, though. Move semantics made my head explode.
TODO: Still a lot of places where errors aren't handled, but it's an improvement...
Ideally, it'd get pushed back into baseband, and baseband would correct for the length of the packet (based on preamble/access code match timestamp minus preamble/access code duration) to give the exact time the packet started.