In order to prevent documentation building issues from being glossed
over, pass the -W command line switch to all sphinx-build invocations.
This causes the latter to return with a non-zero exit code whenever any
Sphinx warnings are triggered.
The ARM and the manpages have been converted into Sphinx documentation
format.
Sphinx uses reStructuredText as its markup language, and many of its
strengths come from the power and straightforwardness of
reStructuredText and its parsing and translating suite, the Docutils.