added metadata to rendermodes, and python bindings for them

src/rendermode-spawn.c

@@ -118,6 +118,7 @@ rendermode_spawn_draw(void *data, RenderState *state, PyObject *src, PyObject *m
 }
 
 RenderModeInterface rendermode_spawn = {
+    "spawn", "draws red where monsters can spawn at night",
     sizeof(RenderModeSpawn),
     rendermode_spawn_start,
     rendermode_spawn_finish,