Pass argc and argv to modules

This lets modules parse options from the command line.
diff --git a/src/xwayland/launcher.c b/src/xwayland/launcher.c
index ddd9640..e50177e 100644
--- a/src/xwayland/launcher.c
+++ b/src/xwayland/launcher.c
@@ -315,7 +315,9 @@
 }
 
 WL_EXPORT int
-module_init(struct weston_compositor *compositor)
+module_init(struct weston_compositor *compositor,
+	    int *argc, char *argv[], const char *config_file)
+
 {
 	struct wl_display *display = compositor->wl_display;
 	struct weston_xserver *wxs;