Cleaning up after adding English (US) to our seeds.

Squashed commit of the following:

commit b901adc818d1af0c9afe70e2449311c52cfd5f12
Author: Ramón Cahenzli <rca@psy-q.ch>
Date:   Thu Oct 16 15:04:29 2014 +0200

    Fixing scenario.

commit 31edb714c36254b7aab679027e2940869bb8241d
Author: Ramón Cahenzli <rca@psy-q.ch>
Date:   Thu Oct 16 14:04:16 2014 +0200

    Fixing aftermath of English (US)

commit 9cbbffc1dabd35440530e444cd38cb9c5311bd1a
Author: Ramón Cahenzli <rca@psy-q.ch>
Date:   Thu Oct 16 12:19:28 2014 +0200

    New test seeds.

commit 46f8e51dbcaceebd8f7bb70de594f1692f7454ef
Author: Ramón Cahenzli <rca@psy-q.ch>
Date:   Wed Oct 15 16:33:27 2014 +0200

    Use correct word for top-level.

commit d5428f7487d17ab541f79d60b48b136af630adf1
Author: Ramón Cahenzli <rca@psy-q.ch>
Date:   Wed Oct 15 15:28:23 2014 +0200

    Mixing languages leads to a lexing error.

commit 13ba79eccb7de27a89f87b1d4aeb30a74c4579e5
Author: Ramón Cahenzli <rca@psy-q.ch>
Date:   Wed Oct 15 15:28:05 2014 +0200

    That doesn't seem to work in Ruby 2.1.3.