This is a cleanup change for bringing setup.py back to our modern coding
standards and to help with maintenance. It adds docstrings where
missing, removes the outdated ez_setup.py support, switches strings to
single quotes, appends "Command" to all command classes, removes the
support for the ancient "nightlies" download page, and fixes up the
setup() call to be better organized and use a more sane indent level.
The Djblets package also has a better description.

Tested package building and develop mode.