[xmonad] Bluetile backport

Hi there! Just wanted to quickly let you know: With the fair number of outstanding patches and a possible repository migration still to do, it seems like a next xmonad release is still a little bit in the future. So I worked on a temporary solution for the meantime and managed to backport Bluetile to work with the xmonad release 0.9.1. So this makes packaging possible/much easier now and Joachim actually already created a package for Debian. I'm excited to see how this can help the Bluetile effort. Thx Joachim! :-) Regards, Jan