Patch to add navigation to first and last image (KDE bug #174619)

[Ivan Wagner]

Please see https://bugs.kde.org/show_bug.cgi?id=174619 for my attempt at
adding this functionality. I made my wife switch from Kuickshow and she
missed these shortcuts.

Thanks,
Ivan Wagner

[Aurélien Gâteau]

Post by Ivan Wagner
Please see https://bugs.kde.org/show_bug.cgi?id=174619 for my attempt at
adding this functionality. I made my wife switch from Kuickshow and she
missed these shortcuts.

Thanks for the patch Ivan, I slightly modified it and committed it!

Aurélien