* Removed type coercion. Options created by argparse are already coerced
to the correct type.
* Removed fallback default values. Options created by argparse already
have a default value.
* Used direct indexing. Options created by argparse are always set. This
eliminates the need to use dict.get().
Also documented missing short command line options to fix#24134. This bumps
the minimum sphinx version required to build the docs to 1.3.4.
Thanks Simon Charette for review.