Michał Dulko e1b254dad1 Fix mistakes introduced with QoSSpecs object
If15ea8b628a6f88211a5d5cc7aadff44f7840138 introduced some mistakes that
I was able to identify when rebasing RequestSpec object patch:

* Missing loading volume_types relationship in QualityOfServiceSpecs
  _from_db_object.
* Wrong source of qos_specs relationship in VolumeType _from_db_object.
* Inefficient loading od QoSSpecs associations in db layer.
* Use of self in classmethod.

This commit fixes the issues.

Change-Id: I3b78127791a03e1a35a30d7f84f66e97d89c7cf9
Closes-Bug: 1603472
2016-07-28 13:34:24 +02:00
..
2015-05-25 22:20:28 +02:00
2016-01-08 11:05:44 -05:00
2013-12-30 18:53:02 -06:00
2013-06-14 14:02:17 +00:00