When invoked without arguments, maascli is too terse

[Gavin Panella]

$ bin/maascli
usage: ./bin/maascli [-h] {api} ...
bin/maascli: error: too few arguments

An invocation without any argument should be a little bit more verbose.

[Raphaël Badin (rvb)]

Looks like changes we made recently made this even uglier (this is running the SRU package on precise):
root@autopkgtest:~# maas-cli
usage: /usr/lib/python2.7/dist-packages/maascli/__main__.py [-h] COMMAND ...
/usr/lib/python2.7/dist-packages/maascli/__main__.py: error: too few arguments

[Gavin Panella (allenap)]

The maas-cli script is:

  #!/bin/sh
  exec python -m maascli "$@"

The original $0 gets lost.

A fix might be to change this script to:

  #!/usr/bin/python
  from maascli import main
  main()