improve speed by turning off some options at spacy_initialize() stage

[kbenoit]

From #90, @amatsuo wrote:

I started working on improving the speed of spacyr_parse() one thing I have tried is to provide an option to exclude ner (named entity recognition) in spacy_initialize(). If the user does not need entity this will speed up by about a third (I can put benchmark results if requested).

This sounds like a great option and could include the same named options from spacy_parse(). If a user wanted to turn on those options in spacy_parse() when they had been disabled from spacy_initialize(), we would print a brief message explaining that they needed to reinitialise spacy with the options turned on.