BEE Backport regress/scripts/cleanup

BEE Backport regress/scripts/cleanup

This commit is the result of the squash of the following main commits:

Author: Norbert Bizet <norbert.bizet@baculasystems.com>
Date:   Fri Mar 22 15:23:16 2019 +0100

    cloud: fix bcloud cleanup

Author: Norbert Bizet <norbert.bizet@baculasystems.com>
Date:   Mon Jan 7 15:03:34 2019 +0100

    Update regress tests for further swift support.

Author: Norbert Bizet <norbert.bizet@baculasystems.com>
Date:   Fri Nov 16 15:33:09 2018 +0100

    regress: Add multi cloud test

Author: Norbert Bizet <norbert.bizet@baculasystems.com>
Date:   Thu Sep 6 11:18:48 2018 +0200

    cloud: add plugin path to bcloud call.

Author: Norbert Bizet <norbert.bizet@baculasystems.com>
Date:   Sat Aug 4 12:55:01 2018 +0200

    regress: Add generic cloud driver to cleanup script

Author: Norbert Bizet <norbert.bizet@baculasystems.com>
Date:   Thu Jul 26 13:55:19 2018 +0200

    cloud: bcloud driver_command handling, based on cloud type

Author: Norbert Bizet <norbert.bizet@baculasystems.com>
Date:   Wed Aug 30 17:38:13 2017 +0200

    improve bcloud for regress tests clean.