Nltk: Deprecating the old Stanford Parser

We have deprecated the StanfordTokenizer/StanfordSegmenter, StanfordPOSTagger and StanfordNERTagger.

It would be good to also deprecate the old StanfordParser, StanfordDependencyParser and StanfordNeuralDependencyParser by

1. Adding the appropriate warnings to the old interface

2a. Wrap the duck-types for CoreNLPParser that emulates the functions of the old interface

2b. Write up documentations of how to use the CoreNLPParser to use dependency and neural dependency parsing

1. Write tests for the new CoreNLP parser interfaces

Both (2a) and (2b) methods should only affect the properties argument of the api_call

The current interface for CoreNLPParser:

>>> from nltk.parse.corenlp import CoreNLPParser
>>> sent = 'The quick brown fox jumps over the lazy dog.'
>>> next(parser.raw_parse(sent)).pretty_print()  # doctest: +NORMALIZE_WHITESPACE
                         ROOT
                          |
                          S
           _______________|__________________________
          |                         VP               |
          |                _________|___             |
          |               |             PP           |
          |               |     ________|___         |
          NP              |    |            NP       |
      ____|__________     |    |     _______|____    |
     DT   JJ    JJ   NN  VBZ   IN   DT      JJ   NN  .
     |    |     |    |    |    |    |       |    |   |
    The quick brown fox jumps over the     lazy dog  .

The desired interface might look like this:

# Using Duck-types
>>> from nltk.parse.stanford import CoreNLPParser
>>> depparser = CoreNLPDependencyParser('http://localhost:9000')
>>> depparser.parse(sent)
>>> ndepparser = CoreNLPNeuralDependencyParser('http://localhost:9000')
>>> ndepparser.parse(sent)

# Using arguments to control `properties` for `api_call()` 
>>> from nltk.parse.stanford import CoreNLPParser

>>> depparser = CoreNLPParser('http://localhost:9000', parser_type="dependency")
>>> depparser.parse(sent)

>>> ndepparser = CoreNLPNeuralDependencyParser('http://localhost:9000', parser_type="neural_dependency")
>>> ndepparser.parse(sent)

This would make a good class project or good first challenge ;P