Replace sphinxcontrib-programoutput with another package

[stevepiercy]

sphinxcontrib-programoutput is no longer maintained and may cause future builds of the documentation to fail.

Replacement candidates include:

• https://pythonhosted.org/sphinxcontrib-autoprogram/
• http://sphinxcontrib-argdoc.readthedocs.io/en/latest/

See #2803

[stevepiercy]

pcreate and other p* scripts use optparse. Neither of the above options are possible solutions because they require argparse.

optparse is deprecated as of Python 2.7.

@mmerickel what do you think about updating p* scripts to use argparse? I found some code that might serve as a pattern to do so.

Our options include:

1. Do nothing. Continue using sphinxcontrib-programoutput.
2. Update p* scripts to use argparse and use one of the above supported Sphinx extensions.
3. Remove documentation that generates the output of the p* scripts.
4. Something else?

[mmerickel]

I can't find any examples of rendered output for http://sphinxcontrib-argdoc.readthedocs.io/en/latest/.

https://pythonhosted.org/sphinxcontrib-autoprogram/ looks fine. Switching to argparse shouldn't be a big deal because they are not extensible commands - no one should be depending on their internal parsing format.

[stevepiercy]

This issue is being worked in #2864

[stevepiercy]

Closed by #2864