+route optimiser
+ performance improvements
+ - select * from buy, sell where
+ buy.commodid==sell.commodid and buy.price > sell.price;
+ and cache the results in core
+ - same for ite
+ - fast version of rsvalue.c ?
+ time ./routesearch -DN 13460 20210 -1 0.005 search 30 7
+ 46.478s without -DN
+ 9.923 9.920 10.026 9.963 10.072 with -DN
+ 9.905 9.935 9.948 9.916 9.997 with debugging compiled right out
+
+create index sell_by_islandonly on sell (islandid, commodid, price);
+
+
+