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).
Added true protection against race conditions on player trades and fixed
some situational issues. Character's quest status table also received
concurrency treatment. Quests with time limit now expires properly.
Increased subtly the performance on the server start-up.
All Guild Alliances system is now functional. Tweaked guilds in order to
sync MapleGuildCharacter objects that were supposed to be the same when
being accessed from both MapleGuild and MapleCharacter classes.
Fixed a issue on server delaying whenever a player gets a new card for
the mobbook. Some code refactoring unifying the several item picking-up
methods on the project.
