Guild PQ + fixed negative EXP error

Implemented Guild PQ. Fixed a problem introduced earlier where negative
EXP would be deemed as "integer overflow", provoking many game breaking
issues as result.

scripts/portal/watergate_open.js

@@ -26,7 +26,7 @@ Stage 3: Exit Door - Guild Quest
 
 function enter(pi) {
     if (pi.getPlayer().getMap().getReactorByName("watergate").getState() == 1) {
-        pi.warp(990000600);
+        pi.warp(990000600, 1);
         return true;
     } else
         pi.getPlayer().dropMessage(5, "This way forward is not open yet.");