MTee Fairseq 0.1.0

This release implements new features required for the MTee project:

• modular multilingual model (language-specific encoders/decoders) enhancements:
  • sharing embeddings in a language-specific way,
  • support training data sampling strategies (including proportional training),
  • support extracting alignments;
• alignments:
  • alignment generation bugfixes,
  • shifted alignment generation (arxiv:2004.14837).