AmoriaPQ + ItemSort fix + revamped GMShop

Implemented AmoriaPQ. Fixed an issue with ItemIdSortHandler where empty
vectors given to the sorting module would cause an exception thrown,
wiping players inventory items. Thanks to Vcoc, revamped shop data for
GMShop (shop id 1337). Mount quest for explorers now uses event script.

scripts/portal/gendergo.js

@@ -0,0 +1,20 @@
+function enter(pi) {
+    var map = pi.getPlayer().getMap();
+    if(pi.getPortal().getName() == "female00") {
+        if (pi.getPlayer().getGender() == 1) {
+            pi.warp(map.getId(), "female01");
+            return true;
+        } else {
+            pi.message("This portal leads to the girls' area, try the portal at the other side.");
+            return false;
+        }
+    } else {
+        if (pi.getPlayer().getGender() == 0) {
+            pi.warp(map.getId(), "male01");
+            return true;
+        } else {
+            pi.message("This portal leads to the boys' area, try the portal at the other side.");
+            return false;
+        }
+    }
+}