Calmjs.parse

------------------

- Modified existing ``setup.py`` hook from an install hook to a build
hook to ensure the generated module files are present. Should any of
those modules are missing and the required dependencies for are not
present (i.e. ``ply`` and ``setuptools``), the build will result in a
non-zero exit status and the documented error message should reflect
which of the required dependencies are missing.

------------------

- Introduce the extractor unparser - an unparser that will unparse a
valid AST into a ``dict``. [
`35 <https://github.com/calmjs/calmjs.parse/issues/35>`_
`38 <https://github.com/calmjs/calmjs.parse/issues/38>`_
]
- Correct the JoinAttr ruletype such that the intended empty definition
value is passed to walk if it was defined as such to avoid an
unintended infinite recursion. [
`36 <https://github.com/calmjs/calmjs.parse/issues/36>`_
]

------------------

- Will now import Iterable from the Python 3.3+ location as the previous
location is marked for removal in Python 3.9. The import will still
have a fallback to the previous location in order to maintain support
for Python 2.7. [
`31 <https://github.com/calmjs/calmjs.parse/issues/31>`_
]
- Provide a test case helper to ensure that the generic ``Program`` repr
signature is provided to assist with test case portability. [
`33 <https://github.com/calmjs/calmjs.parse/issues/33>`_
]
- In the ``calmjs.parse.vlq`` module, implemented the ``decode_vlq``
helper for completeness/symmetry to the ``encode_vlq`` helper. [
`33 <https://github.com/calmjs/calmjs.parse/issues/33>`_
]

------------------

- Correct usage of ``__doc__`` to support level 2 optimized mode. [
`29 <https://github.com/calmjs/calmjs.parse/issues/29>`_
`30 <https://github.com/calmjs/calmjs.parse/issues/30>`_
]
- Corrected some minor string definition syntax, where raw string prefix
should be used but was not previously.

------------------

- Correctly include LICENSE file in sdist. [
`27 <https://github.com/calmjs/calmjs.parse/issues/27>`_
`28 <https://github.com/calmjs/calmjs.parse/issues/28>`_
]
- Include the correct test data general form for some previously added
test cases to better accommodate already planned future features.

------------------

- Fix the issue of failures with regex statement that occur due to lexer
being in a state where the disambiguation between REGEX or DIV token
types is not immediately possible, as tokens such as RBRACE, PLUSPLUS
or MINUSMINUS must be consumed by parser in order to be disambiguated,
but due to the lookahead nature done by yacc, the DIV token will be
prematurely produced and the only way to achieve this is during the
error handling stage. [
`25 <https://github.com/calmjs/calmjs.parse/issues/25>`_
`26 <https://github.com/calmjs/calmjs.parse/issues/26>`_
]
- Part of the previous fix also removed newline or comment tokens from
being reported as part of parsing error messages.