Pyhpo

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- Added GraphIC similarity measure

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- Added Orphanet diseases to Annotation
- Added Decipher diseases to Annotation

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- Reworked BasicHPOSet
- Added omim_diseases to HPOSet
- Added distance method to similarity measurement
- Added equal measurement to HPOSet similarity

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- Refactored Ontology to act as a singleton
- Able to remove some weird dependencies when creating HPOSets
- Refactored some unit tests to only temporarily mock methods
- Performance improvements through using more cached objects
- Making HPOSet an actual set
- Adding BasicHPOSet
- Handling obsolete terms

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- Added serialization to HPO Term and HPO Set
- Option to remove modifier from HPO Set
- Changed Omim and Gene to be Singletons

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- Data update
- HPO: 14961 ==> 15332
- Genes: 4312 ==> 4317
- OMIM: 7623 ==> 7675
- Negative OMIM: 634 ==> 638