Seq2SeqSharp v2.5.0

[zhongkaifu]

A couple of important upgrades are included in this package, such as

1. Pointer generator
2. Decoding prompting
3. Optmized decoding strategy
4. Tag embeddings
5. ProtoBuf supporting
6. Build-in SentencePiece calling
7. Web application/apis
8. And so on.

The demo package is also updated and more new applications are included.

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This discussion was created from the release Seq2SeqSharp v2.5.0.