Fix guest user access to public pdfs

Squashed commit of the following:

commit 418938a7cac1408c6f62b7220c8a8da50893787e
Author: Jonasz Grochowski <tensaioni@gmail.com>
Date:   Mon Aug 18 09:01:47 2014 +0200
Add legacy media_entries and media_set routes

Squashed commit of the following:

commit 7704e0d7cd6500ce95fcb6940e9f2a34e1a83dff
Author: Jonasz Grochowski <tensaioni@gmail.com>
Date:   Fri Sep 12 11:34:57 2014 +0200
Export low resolution video rather than jpeg thumbnail

Squashed commit of the following:

commit 831bbdae4ea4e76c39d697d170ec92581e0f1379
Author: Michał Podlecki <m.podlecki@op.pl>
Date:   Tue Sep 16 12:17:20 2014 +0200
Set version to 2.2.0-beta.0