xorg.libXfont: security update, CVE-2014-{0209,0210,0211}

For details see http://lists.x.org/archives/xorg-announce/2014-May/002431.html

(cherry picked from commit 832c66182232a2ecfe5a0f63629804274bc73902)
mupdf: fix patch hash by fetchpatch

Thanks to @kirelagin for reporting on IRC.

(cherry picked from commit f77e2dcb387637aea3a304c404867d27f91bccb8)
Added bspwm and sxhkd exppression
Merge branch 'bspwm' of github.com:ellis/nixpkgs into bspwm