Add "--network-segment" option to the "subnet create" command.
This is a beta command option and subject to change. Use global
option "--os-beta-command" to enable this option.
This patch set also provides a devref update for beta command
options.
Change-Id: I4d0fbe079b2a873307364c41c22ce9ba88e632e6
Partially-Implements: blueprint routed-networks
The --enable option on commands is ignored when the arguments are parsed.
This is related to the --enable-beta-commands option. Renaming the option
to --os-beta-command fixes the problem.
There's no need to handle backwards compatibility for the option name
change because there hasn't been an OSC release yet with beta commands.
Change-Id: I0327ba8a2058858a83e9a42e231470ed733cc834
Closes-Bug: #1588384
