Having the docs index in the repo root was a holdover from when it was
the README file. Now that it's not much use without being built, it's
better to leave the root to README, NEWS, and LICENSE - especially when
one is a html shortcut to the docs index.
Expands coverage of scripts linting, and improves checks for a correct
title. Various fixes to make 'python travis/all.py' work for offline
users; when the TRAVIS envvar is not set it now fails without an error.
Minor cleanup in conf.py