This changes every command-line option with a '_' in its name
and changes them to '-'. The old option names are maintained
for backward compatibility but are no longer in the help text.
BP command-options
Note: there is a dodgy hack in novaclient/shell.py to handle
usage-list's --end option that conflicts with --endpoint-type
if --endpoint_type is also present for backward compatibility.
If --endpoint_type is not added to the parser it works. Go figure.
Better solutions that do not break backward compatibility are welcome.
Rebased due to https://review.openstack.org/11072 merging.
Note: --availability_zone changed to --availability-zone with no
backward compatability since this s a new option.
Change-Id: I09ab546659be0a0d3f0eadb22ab5e13fac2f059d