Admin interface: meta-terms improvements

Squashed commit of the following:

commit fe19c68b09111ffad52b25bf1fe26b9700573e11
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Mar 25 14:01:52 2014 +0100

    add a reset button that clears all searching, filtering and sorting

commit b87309f5320b6edef804c76ded122e90e2811fe4
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Mar 25 11:44:48 2014 +0100

    additional feature tests for remembered params

commit 15a64635c3316b6903311abcbed1eef95e0d6700
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Mar 25 10:16:50 2014 +0100

    ignore .ruby-gemset file

commit 0cd34414d0d368d79bffcdd2ccccf768de88911a
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Mar 25 10:16:30 2014 +0100

    fix broken feature tests

commit 4ea16e8ef77d1438ffb8a4c8f542cd636439bdf7
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Mar 25 10:05:19 2014 +0100

    remember url params between meta_terms' actions
Admin interface: settings improvements

Squashed commit of the following:

commit 703127f7cee5a0a3a3a68df12b61d41e4143c896
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Thu Feb 13 15:06:51 2014 +0100

    Squashed commits:

    show settings page as index view

    add edit links on settings page

    settings are editable via their edit pages

    edit media set on its details view

    fix broken feature tests