Squash-merge pull request #148 from mattip:2.4

Squashed commit of the following:

commit 66e859546548fca0e336fa111c87d59fc8ab6e5d
Author: Matti Picus <matti.picus@gmail.com>
Date:   Thu Feb 20 22:14:37 2014 +0200

    update images to be more random

commit 1e361be388cbfbdaf02eb4376375da3af0df5994
Author: Matti Picus <matti.picus@gmail.com>
Date:   Thu Feb 20 22:13:54 2014 +0200

    add files for tiled tiff tests