Please document fields that can be used with 'query' and 'filter' flags

[Yurii Prokulevych]

Some commands allow to use '--filter'/'--query' arguments.
Please update documents(like developer's guide) or help message with allowed field.

Cuz currently it doesn't provide exhaustive info. E.g:

aodh alarm-history search --query "name='AClient-Threshold-1'"
Filter expression not valid: {u'=': {u'name': u'AClient-Threshold-1'}} is not valid under any of the given schemas (HTTP 400) (Request-ID: req-00f522b9-78ef-4975-b401-ca5b2651bded)

And the help message:
aodh alarm-history search --help
...
  --query QUERY Rich query supported by aodh, e.g. project_id!=my-id
                        user_id=foo or user_id=bar
...

Packages:
aodhclient==0.4.0

Regards,
Yurii