Provide wrapper for sphinx-build

[waywardmonkeys]

Look at providing a wrapper for sphinx-build that customizes some settings for Dylan documentation builds, like defaulting the theme or the theme search paths.

[cgay]

Thoughts:

• The gendoc library generates combined documentation for all published packages, ameliorating this somewhat, since it means that only the conf.py in gendoc is used. Of course, sometimes one wants to build one's own docs and publish them separately, so...
• dylan new library should generate initial documentation, probably by invoking sphinx-quickstart with most/all of the fields filled in and fail in a friendly way if sphinx-quickstart is not present.

[cgay]

I think we can close this now that Deft generates Sphinx doc with an appropriate config for Dylan.