only reenable spawns when the party has moved away some

If the spawn point is just out of sight it often respawns immediately,
attacking the party that is moving away from it from behind.

gemrb/core/Map.cpp

@@ -3109,8 +3109,10 @@ void Map::UpdateSpawns()
 	for (std::vector<Spawn *>::iterator it = spawns.begin() ; it != spawns.end(); ++it) {
 		Spawn *spawn = *it;
 		if ((spawn->Method & (SPF_NOSPAWN|SPF_WAIT)) == (SPF_NOSPAWN|SPF_WAIT)) {
-			//only reactivate the spawn point if the party cannot currently see it
-			if (spawn->NextSpawn < time && !IsVisible(spawn->Pos, false)) {
+			//only reactivate the spawn point if the party cannot currently see it;
+			//also make sure the party has moved away some
+			if (spawn->NextSpawn < time && !IsVisible(spawn->Pos, false) &&
+				!GetActorInRadius(spawn->Pos, GA_NO_DEAD|GA_NO_ENEMY|GA_NO_NEUTRAL, SPAWN_RANGE * 2)) {
 				spawn->Method &= ~SPF_WAIT;
 			}
 		}