Miditok

Changes:
* c3d6c89ef0e69159614079c144af6684a7dca192 new attribute tokens_types_graph for every class, to be used to check if a generated sequence is made of valid token successions
* bd9aade3b5ce263ab90c7276e4b57b287047cdf3 Program token type is part of additional_tokens attribute. MidiTok never use them, its here for you if you need it

Compatibility:
* _create_token_types_graph is called by MIDITokenizer's constructor, your custom classes should then implement it (can return None)
* Your datasets tokenized with <= v1.1.0 will stay compatible but you won't be able to load them without adding the 'Program' key in the config.txt files.

* 5826734593e20414f4b3eb5f6048daabf39b5c2c New Vocabulary class handling vocabulary creation, and event <--> token mapping
* ea4965612fc650a389dab4b19fe222ae0d1b50e7 SOS and EOS tokens are not included by default, sos_eos_tokens let you handle this
* 9a9db25cc8427504b5b579d6620dd777bbb75869 save_tokens and load_tokens methods
* 9a9db25cc8427504b5b579d6620dd777bbb75869 bugfix in detect_chords with only_known_chord param

* 7558381940d8a0e83ad485fdb3c3a24ba27674c0 Bugfix when no tempo tokens were used

Big update, tokens saved with v0.1.8 and before will not be compatible anymore (except with Structured encoding)

* New Rest tokens for Remi, MIDI-Like and CP Word ! See readme for details
* Empty tokens are removed (replaced by rests)
* SOS and EOS tokens added by default in vocabularies, add_sos_eos_to_seq adds them to your sequences
* More advanced tests ! (still to be improved !)
* e10277f74e48a4e7d59941f08c7b2c100ff3f44c 5b596c7f9851f47e178740c872bc8b04df43c2da Velocity and Tempo tokens are represented by their value in vocabularies, instead of indexes before which added unnecessary extra steps
* efbe4a0720971af1b1f8bc5431837ef392aed208 e10277f74e48a4e7d59941f08c7b2c100ff3f44c quantize_notes optimized, and now quantize also velocities and remove out of range pitches
* 67802e0aca5f41e3cbebfdf5218fcd5abbdb4dfb detect_chords optimized, samples_scopes, simul_notes_limit and only_known_chord parameters added
* 8b2b0f8b72f47cd11499b83f2877153dd2584313 MIDI time division check when tokenizing a dataset
* 2c27d7db94bc1bad38a5f9a9b4f74955c1e1c9e4 Bugfix in Structured
* e10277f74e48a4e7d59941f08c7b2c100ff3f44c Bugfix in Midi-Like
* More minor bug fixes hidden in commits 👀

* Bugfix c7fcabdba16e9215b088ecda78bd054e68aa8696 position value with non divisible time division
* Bugfix bada26de68142e91c1dbbc55e7529aca7aa80d10 and ad1ef6ef697fbc694eeaf56ada1647c1c4061708 now checking drum pitches are valid for MuMIDI

* bugfix in save params for octuple/mumidi 0ef15d986940b6687fabe9520567e6780d302e0a