nova.py: Remove DOCUMENTATION block

@mpdehaan said that nothing uses them at
https://github.com/ansible/ansible/pull/7988#issuecomment-47600006
Correct typo: 'additioanl' -> 'additional'
Correct typo: 'receords' -> 'records'

I should read more than a sentence at a time when I'm correcting typos—sorry for the typo correction spam ;)
nova.py: indented and sorted JSON output
Further safe_eval fixes
When parsing json from untrusted sources, remove templating tags
CHANGELOG and other updates for 1.6.6 release
Merge pull request #7993 from msabramo/nova.py_Remove_documentation_block

nova.py: Remove DOCUMENTATION block
Merge pull request #7994 from adamnbowen/patch-2

Correct typo: 'additioanl' -> 'additional'
Merge pull request #7995 from adamnbowen/patch-3

Correct typo: 'receords' -> 'records'
Merge pull request #7996 from msabramo/nova.py_JSON_indented_and_sorted

nova.py: indented and sorted JSON output
Improvements to OpenStack inventory script
nova.py: Set defaults for OpenStack settings

- auth_system
- region_name
- service_type

These are config settings that could be left out in many scenarios, but
the current code is requiring them. In particular, "service_type" is a
new one in PR #7444 so if we add that and don't set a default, then
existing .ini files won't work:

```
  File
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ConfigParser.py",
line 618, in get
    raise NoOptionError(option, section)
ConfigParser.NoOptionError: No option 'service_type' in section:
'openstack'
```
nova.py: Support OS_AUTH_SYSTEM and OS_REGION_NAME
nova.ini: Distinguish between required and optional settings

Put them in separate sections of config to make it more clear what is
essential and what is not. Also comment out the optional settings.
And remove duplicate mention of `service_type`.