* Refactor tokenization, splitting it into a clearer life-cycle.
* Refactor tokenization, enable cache, and ensure we look up specials correctly even when there's confusing punctuation surrounding the token.
* Add memory management code
* Switch to using a Python ref counted gateway to malloc/free, to prevent memory leaks
* Switch from own memory class to cymem, in pip
* Remove own memory classes, which have now been broken out into their own package
* Add typedefs file
* Use PointerHash instead of locally provided _hashing module
* Remove old docs stuff
* Add prefix and suffix data files
* Add util.py
* Add German tokenizer files
* Add extra tests
* Remove ptb3 file from setup
* Re-add docs, sorting out mess from gh-pages
* Remove hashing modules, which are now taken over by external lib
* Rename external hashing lib, from trustyc to preshed
* Upd docs
* Add i attribute to lexeme, giving lexemes sequential IDs.
* Add serialize/deserialize functions for lexeme, transport to/from python dict.