[#41276413] Filter by MediaResource types

Squashed commit of the following:

commit 46d06c28893ca570fef4806b6d9ca1418ba29634
Author: Sebastian Pape <email@sebastianpape.com>
Date:   Thu Mar 28 15:19:25 2013 +0100

    finish integration test

commit 2a3941dbfbc1d6d29f66af43fbb1c2559cf764bc
Author: Sebastian Pape <email@sebastianpape.com>
Date:   Thu Mar 28 14:35:15 2013 +0100

    finish implementation of mr types to filter panel

commit 04d4d1066a4bca666b08cf57df249ef5ee949780
Author: Sebastian Pape <email@sebastianpape.com>
Date:   Thu Mar 28 13:45:11 2013 +0100

    [WIP] new filter for media resources type

commit 14cb8a84908e829b1b75ac72dccda2fde91b93dd
Author: Sebastian Pape <email@sebastianpape.com>
Date:   Thu Mar 28 13:20:21 2013 +0100

    do not response with empty filter