Fixes 288 - xinerama crashing bug on non-xinerama screens
Fixes 288 - xinerama crashing bug on non-xinerama screens

There's a possibility of a null pointer returned by
XRRGetScreenResources in mod_xrandr_get_outputs_for_geom. It wasn't
getting checked. Now it is.

raboof/notion,knixeur/notion,knixeur/notion,knixeur/notion,knixeur/notion,raboof/notion,knixeur/notion,raboof/notion,raboof/notion