light: store bsp in lightsurf for convenience

include/light/light.h

@@ -95,6 +95,7 @@ typedef struct {
 /*Warning: this stuff needs explicit initialisation*/
 typedef struct {
     const modelinfo_t *modelinfo;
+    const bsp2_t *bsp;
     const bsp2_dface_t *face;
     /* these take precedence the values in modelinfo */
     lightsample_t minlight;

light/ltface.c

@@ -855,6 +855,7 @@ Lightsurf_Init(const modelinfo_t *modelinfo, const bsp2_dface_t *face,
         /*FIXME: memset can be slow on large datasets*/
 //    memset(lightsurf, 0, sizeof(*lightsurf));
     lightsurf->modelinfo = modelinfo;
+    lightsurf->bsp = bsp;
     lightsurf->face = face;
     
     if (facesup)