[ADD] doc: JS document extraction system

* Fix a bunch of ill-documented/incomplete/incorrect method docs
* add start of Sphinx extension to extract & integrate jsdoc into
  Sphinx documentation:

  - parse JS files (and don't blow up), uses a fork of pyjsparser as
    the project currently does not parse comments
  - extract cross-module dependency information
  - parse JsDoc comments using pyjsdoc and infer structure from code &
    jsdoc
  - ``ast`` CLI printing a simplified AST of the input files
  - ``dependencies`` creating a dependency graph of either all modules
    in the provided input files or the modules matching the specified
    filters (warning: will not work if missing dependencies),
    generates a .dot file
  - ``extractor`` generating a plain text module documentation (mix of
    rst and markdown styles, not anything formal)
* sphinx extension with an "automodule" directive taking a module name
  and generating the documentation for it