Admin interface: use autocomplete to change responsible person of a set

Squashed commit of the following:

commit b1f4219d3ecd8ddab7493d6c407dd4b9f777adb0
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Aug 26 10:46:22 2014 +0200

    Admin interface: use autocomplete to change responsible person of a set
ui: set: resources view: js: saving the display settings: visual feedback, error handling
ui: import: warn about CMYK images
ui: js: #fix visualization_layout_web_worker.js asset path handling

part of Rails 4 upgrade!
Upgrade rails and some other gems

Squashed commit of the following:

commit f95f8baa0d8f0177aa8341c23944ef8e8a83a7e7
Author: Thomas Schank <DrTom@schank.ch>
Date:   Tue Sep 2 09:49:15 2014 +0200

    Fix font-awesome after upgrade

commit d4bdd70c46bca57f4a39a88abaf3930fe3c3bade
Author: Thomas Schank <DrTom@schank.ch>
Date:   Tue Sep 2 09:35:01 2014 +0200

    Upgrade jquery of the admin interface

commit 9fd514e64247e7ea37f5943e47813d1348925af3
Author: Thomas Schank <DrTom@schank.ch>
Date:   Mon Sep 1 15:12:52 2014 +0200

    Downgrade capybara and rspec

commit 1525ef47d4f7d88f94e1bd8b9b56188c29f7abf7
Author: Thomas Schank <DrTom@schank.ch>
Date:   Mon Sep 1 14:48:23 2014 +0200

    Configure locales

commit 282ad20798983b723736d859d1cf3237f51911c6
Author: Thomas Schank <DrTom@schank.ch>
Date:   Mon Sep 1 14:28:11 2014 +0200

    Upgrade capybara too

commit 5c04297f902eb0953c1f5f9d1b8379c86d3501d5
Author: Thomas Schank <DrTom@schank.ch>
Date:   Mon Sep 1 14:15:38 2014 +0200

    Upgrade rails and gems
Update jquery for the api docs (failed assets compilation)
Fix admin tests
Change icons from glyphicons to fontawesome
Set stable version to 2.0.12
Move newrelic config to template and gitignore it

so ansible will be ok with it
Set version to 2.0.13; move sem version to config/settings and diplay it in footer
Admin interface: fix switch to another admin user button