As discussed in https://review.openstack.org/#/c/36352/ for each
command, we were setting api = identity or volume... etc,
this was for an old way of calling commands that are is no longer
used.
Also removed openstackclient/common/command.py
Change-Id: I2705f35d343f2ae729dc22d6aed0b852b2f8ca19
Made all the necessary changes to pass new PEP8 standards.
Also cleaned up docstrings to conform to the HACKING stanards.
Change-Id: Ib8df3030da7a7885655689ab5da0717748c9edbe