Subpackage refactor. Fix 1584

[menshikh-iv]

Fix for #1584.

[menshikh-iv]

What's done:

• Removed gensim.examples

• Removed gensim.nosy

• Scripts:

  • Removed from gensim/scripts (because all of this is duplicates)
    • make_wiki_lemma.py
    • make_wiki_online.py
    • make_wiki_online_lemma.py,
    • make_wiki_online_nodebug.py
    • make_wiki.py
  • Rename gensim/scripts/make_wikicorpus.py -> gensim/scripts/make_wiki.py
  • Removed word2vec_standalone.py

• Moved gensim.topic_coherence to gensim.models._coherence

• Moved gensim.summarization to gensim.models.summarization

• Moved gensim.utils to gensim.utils.utils (with imports in gensim/utils/__init__.py, no differences for users)

• Moved with raneming gensim.parsing.* to gensim.utils.text_utils

• Fixed doc structure (according to changes)

I re-create PR according to discussion from #1607 and #1584, please review again @piskvorky @macks22

[piskvorky]

Regarding the various make_wiki_*.py duplicates: these were originally symlinks. They became duplicates (regular files) only by error of a committer.

Removing them will break some functionality, because the make_wiki script behaves differently based on what filename it was run as.

These parameters are probably better served as proper CLI options, rather than encoded in the filename. Just saying that simply removing the "duplicates" will prevent users from accessing existing functionality.

[menshikh-iv]

@piskvorky
All different behavior implemented through this arg, that's very bad, why not concrete CLI option? I'll fix it.

[menshikh-iv]

Close (because conflict is really big), I'll re-create it with additions when we plan to create major release