Water of Life + Fixed GPQ & Buff system

Added Water of Life. Fixed Shuang (GPQ) npc dc'ing the leader when first
trying to enter the waiting area. Fixed some cases with the revamped
buff system, that would not properly check for the best buffs in some
scenarios, and would throw exceptions, caused by not properly protecting
access to critical data.

docs/feature_list.txt

@@ -32,7 +32,7 @@ Quests:
 * Quests can now reward properly items when matching a reward item with the player's job.
 * Loads of quests have been patched.
 * Quest rewards according to jobs works properly.
-* Rewarding system now checks for stacking opportunities on the inventory before checking for new slots.
+* Enchanced rewarding system: checks for stacking opportunities on the inventory before checking for new slots.
 
 Player Social Network:
 * Guild and Alliance system fully functional.
@@ -60,6 +60,7 @@ Server potentials:
 * Mastery book announcer displays droppers of needed books of a player, by reading underlying DB.
 * Every skill/mastery book is now droppable by mobs.
 * Inventory auto-gather and auto-sorting feature.
+* Enhanced buff system: smartly checks for the best available buff effects to be active on the player.
 * Enhanced AP auto-assigner: exactly matches AP with the needed for the player's current level, surplus assigned to the primary attribute.
 * Added Boss HP Bar for dozens of bosses (needs provided custom wz).
 * If multiple bosses are on the same area, client will prioritize Boss HP bar of the target of the player.