make regions age only once someone discovers then

src/kernel/region.c

@@ -791,7 +791,7 @@ region *new_region(int x, int y, struct plane *pl, int uid)
 {
     region *r;
     r = region_create(uid);
-    r->age = 1;
+    r->age = 0;
     add_region(r, x, y);
     assert(pl == r->_plane);
     return r;

src/laws.c

@@ -810,7 +810,9 @@ void demographics(void)
     season_t last_weeks_season = calendar_season(turn - 1);
 
     for (r = regions; r; r = r->next) {
-        ++r->age; /* also oceans. no idea why we didn't always do that */
+        if (r->age>0 || r->units || r->attribs) {
+            ++r->age; /* also oceans. no idea why we didn't always do that */
+        }
         live(r);
 
         if (!fval(r->terrain, SEA_REGION)) {