Reworked autoassigner (improved limits between required secondary and
surplus primary stats). Hero's will removes most of diseases, tonic
removes slow. Added visual info for collected NX cards. Added commands
cake (cake boss with customizable HP) and setgmlevel. Reworked Trade
system now checking for slots smartly (instead of just checking for
empty slots).
Added mechanics for the EXP/DROP cash coupons (such as enabling
out-of-time active coupons via command and automatic update of active
ones over the designed interval). Created MapleCouponInstaller as means
to gather info about the coupon intervals and rates from the WZs (the
generated SQL table is already updated on the db_database.sql file).
