New PQ: Boss Rush PQ + Ellin/PiratePQ bug fixes

Introducing Boss Rush PQ. Corrected a few issues regarding rewardings in
PiratePQ and EllinPQ and implemented a standardized way to script PQs.

sql/tools/test_duplicates.sql

@@ -0,0 +1,2 @@
+SELECT dropperid,itemid FROM drop_data d WHERE EXISTS
+  (SELECT * FROM drop_data e WHERE (d.id != e.id AND d.itemid=e.itemid AND d.dropperid=e.dropperid)) group by itemid,dropperid;