Squashed commit of the following:

commit 4b53d6ef353b2398720ae3222708b3466b32fc21
Author: Benjamin Kiessling <mittagessen@l.unchti.me>
Date:   Fri Jul 4 16:45:38 2014 +0200

    Turns out compiling is not equal to functionality tests. Who would've
    thought?

commit 082e1bbfd8f990ea3d11ed9b3b42b7c304ac06cd
Author: Benjamin Kiessling <mittagessen@l.unchti.me>
Date:   Fri Jul 4 14:20:16 2014 +0200

    Actually add rgb_to_gray function to module

commit 84703449f6f07572c2ef1c7fe63b086f264d7ae2
Author: Benjamin Kiessling <mittagessen@l.unchti.me>
Date:   Mon Jun 30 15:09:40 2014 +0200

    Add rgb_to_gray wrapper

commit 547205de64435eda2d3f081a985a5fc8040b2bf4
Author: Benjamin Kiessling <mittagessen@l.unchti.me>
Date:   Mon Jun 30 14:50:46 2014 +0200

    Fix init function

commit aa9ed9d5b1ec48d57b172473272a7ccaeca91146
Author: Benjamin Kiessling <mittagessen@l.unchti.me>
Date:   Mon Jun 30 14:44:21 2014 +0200

    Update setup.py for new c extension

commit 6d0ed9ee79b44f2ab00262a10d2ba89838aa29e8
Author: Benjamin Kiessling <mittagessen@l.unchti.me>
Date:   Mon Jun 30 14:35:41 2014 +0200

    deskew is now leper and does binarization(s)