Admin interface: filtering zencoder jobs by failed state
Improve error handling, add tests
Add tests for media set highlights, cover and content display mode
Admin interface: delete groups, merge inst. groups

Admin interface:
- add delete button in groups list
- ability to merge institutional groups

Squashed commit of the following:

commit c094cf96363080950283a10cf8dc15eaac4e8ef0
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Wed Nov 12 13:05:25 2014 +0100

    Admin interface:
    - add delete button in groups list
    - ability to merge institutional groups
Add cider_ci-rails gem
ui: relations: visual fixes

fixes [#82170730]

Squashed commit of the following:

commit 0f9821cf0f8ab3415638506fb8b8f91f52aff59c
Author: Max F. Albrecht <1@178.is>
Date:   Wed Nov 12 12:36:32 2014 +0100

    adjust test

commit da447ad784e8cf06621066db55f37aff280b8d72
Author: Max F. Albrecht <1@178.is>
Date:   Wed Nov 12 12:27:47 2014 +0100

    ui: css: fix .ui-resources.grid.horizontal vertical alignment

    li items were ragged if they had content of different lengths

commit 30eb306ed1d29e0d7a4873f43d054d0f5063cd3a
Author: Max F. Albrecht <1@178.is>
Date:   Wed Nov 12 11:54:38 2014 +0100

    relations: resource-link point to #show, not #relations

commit f0bd600630394da7c1b41d29364ad41c126ccbce
Author: Max F. Albrecht <1@178.is>
Date:   Wed Nov 12 11:54:11 2014 +0100

    relations: remove line breaks from description
Add access for public users to cutom urls page (if have such permission)