experimenting with storing bytes internally, rather than unicode

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experiment: store internally as unicode, but write to binary streams. tests passing

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simplify internal type handling. unset .coercer to disable coercing, rather than using the .coerce_values flag

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tests: fixed typo
parsing in binary but storing internally as unicode

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binary shortcutting working. all tests pass

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actually merged bytes branch
docs: updated bytes info
removed caching in anticipation of a reimplementation using lru_cache