Convert generate_options.pl to python.

[kvdveer]

I noticed that Options.rst was outdated, it was missing several items that were defined in source code

For many options, Options.rst is the only page on the internet that mentions them. This causes that page to receive a lot of search traffic, despite it being a very poor source of information (as mentioned in the intro). Because of this, I'm planning to update this to be a better source of documentation. This will involve quite some code, as I'm not a Perl-expert, I decided to convert generate_options.pl to python. As this project builds on sphynx, python is already a dependency, making it a better match than Perl. These days, python developers are more common than Perl developers, so this broadens the audience a bit, too.

Regenerated Options.rst against uwsgi 2.0.28, which is the latest version on pypi at the time of writing.

This PR is 'testing the waters' to see if the project is interested in the contributions i'm planning. Feel free to redirect my efforts elsewhere. My plans for the future include:

• Combine options that are aliasses of each other (e.g. socket and uwsgi-socket). This will substantially reduce the number of options.
• Interpreting common func arguments, to provide a more human-readable experience
• If possible: automatically generate documentation links to existing rst files.

I also plan on improving other documentation content unrelated to Options.rst, but as this is the main file in most google searches, I feel my effort should primarily be spent there.