Add force_xinerama configuration option

The configuration option does the same as the commandline parameter, except
it can be easily set by the user (e.g. you are using KDM and can't start a
session through ~/.xsession).

Signed-off-by: Michael Walle <michael@walle.cc>

src/main.c

@@ -432,7 +432,10 @@ int main(int argc, char *argv[]) {
 
     free(greply);
 
-    if (force_xinerama) {
+    /* Force Xinerama (for drivers which don't support RandR yet, esp. the
+     * nVidia binary graphics driver), when specified either in the config
+     * file or on command-line */
+    if (force_xinerama || config.force_xinerama) {
         xinerama_init();
     } else {
         DLOG("Checking for XRandR...\n");