query_to_kwargs inconsistent behaviour on invalid input

[gordon chung]

relating patch to add testcases for _query_to_kwargs() function, invalid operators and fields will give different results

if you have an invalid field but valid operator ('eq'), an UnknownArgument is raised
if you have an invalid operator but valid field, a warning is logged but query continues to be processed
if you have invalid field and invalid operator, invalid operator takes precedence, warning logged, and query continues.

i don't think invalid operator should hide the invalid field error. we should probably be raising for invalid operator and invalid field.

thoughts?

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/43796

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/43796
Committed: http://github.com/openstack/ceilometer/commit/05db82ac1b7ca8b32228844eddaf8f23faae2ab0
Submitter: Jenkins
Branch: master

commit 05db82ac1b7ca8b32228844eddaf8f23faae2ab0
Author: Gordon Chung <email address hidden>
Date: Mon Aug 26 18:40:36 2013 -0400

    add tests for _query_to_kwargs func

    add test case for _query_to_kwargs function in v2 api.
    raise InvalidInput on invalid operator

    Change-Id: Ia9e9b3905327d21e3c6f91aa0acd36f19f4f59b0
    Partial-Bug: #1217129