Comment 7 for bug 1518979

Reviewed: https://review.openstack.org/267508
Committed: https://git.openstack.org/cgit/openstack/fuel-qa/commit/?id=fec8282ec442571e251e509bc3c3677dba6b7a5e
Submitter: Jenkins
Branch: master

commit fec8282ec442571e251e509bc3c3677dba6b7a5e
Author: Alexey Stepanov <email address hidden>
Date: Tue Jan 12 15:57:48 2016 +0300

    Minor refactor

    1. SingletonMeta -> modified to allow handling multiple classes and moved to metaclasses too.
    2. @logwrap : process asserts too

    Changes reason:
     @logwrap was changed during test debug (was assert in wrapped function
     and stacktrace was not enough for reason understand) and moved out of
     test changest due to not mandatory for this test.
     Pros: Now assert, raised in wrapped function is recorded in log with
     details.

     SingletonMeta: was changed as "nice to have" during work on plugin
     helpers. Later plugin helpers was moved out of SshManager, and all code
     changes was moved to this changeset.
     Pros: Single way for handling the same tasks in different places.
     Previously SshManager used Metaclass, which could not be reused for
     more, than one class and Environment used __new__ directly written
     in class code.

    Related-Bug: #1518979
    Related-Bug: #1519050

    Change-Id: I798302879400747909229cc208f97a669f25bbf3