Make ManagerWithFind abstract and fix TokenManager

ManagerWithFind requires list() method in its descendants.
Make it abstract and fix its improper descendant TokenManager
that do not implement list().

Change-Id: I83ae47d894c02d5cd1eb0da437dd05796d0b0160
Fixes: bug #1180393
Missing command descriptions for 'token-get' and 'endpoint-get'

When using command "keystone help token-get" and "keystone help endpoint-get",
the description of these commands are missing. The main reason is that
keystoneclient is using the command action method's method doc as the command
description. In keystoneclient/v2_0/shell.py, the two commands' action method
are 'do_endpoint_get' and 'do_token_get'. These two methods have a decorator of
"require_service_catalog" which is a function wrapper, and this decorator has
changed the origin __doc__ of the wrapped function by default

Modify "require_service_catalog" to change the __doc__ back to the origin
function's __doc__

Change-Id: I9977a3d279529b2066667cd2ffe44dd953b4d2fb
Fixes: Bug 1182107
Enumerate ignored flake8 rules

We were previously ignoring all F* and H* rules; this patch specifically
identifies them so that we can eliminate them one by one, without
introducing regressions along the way.

Change-Id: Iaf9ee17acf44aba1c93c1af50c84bd8216544b89
Merge "Missing command descriptions for 'token-get' and 'endpoint-get'"
Merge "Make ManagerWithFind abstract and fix TokenManager"
Merge "Enumerate ignored flake8 rules"
Fix --version to output version

Change-Id: I7d8dc83ac7c2ad7519633d136c1c32ce8537dce8
Fixes: bug 1182675
Fix line continuations (flake8 E125, E126)

- E125: continuation line does not distinguish itself from next logical
  line
- E126: continuation line over-indented for hanging indent

Change-Id: I626a6d5d57db927e8b239f90569b5601c772f28b
Fix unused imports(flake8 F401, F999)

- F401: imported but unused
- F999: syntax error in doctest

Fixing a couple of the F401's simply required fixing the doctests syntax
where the imports were actually in use.

Change-Id: If78abbb143daf8d005a71c5ab52836df29c5e0cd
Merge "Fix line continuations (flake8 E125, E126)"
Merge "Fix --version to output version"
Merge "Fix unused imports(flake8 F401, F999)"