Fixed an issue that would let a player to delay or anticipate the next
map hpDec proc in certain conditions. Implemented mechanic that enables
the DB save of expiration times for quests that needs this.
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.
