[7393] Implement access to client side holiday ids. Author: VladimirMangos

* src/game/GameEvent.* renamed to src/game/GameEventMgr.* for consistence
    * `game_event` now have new `holiday` field for store client side holiday id associated with game event
    * Added new enum HolidayIds with existed at this moment holiday ids.
    * New function "bool IsHolidayActive(HolidayIds id)" added accessabel from scripts for active holidays check.

--HG--
branch : trunk

src/shared/Database/DBCfmt.cpp

@@ -55,6 +55,7 @@ const char GtOCTRegenHPfmt[]="f";
 //const char GtOCTRegenMPfmt[]="f";
 const char GtRegenHPPerSptfmt[]="f";
 const char GtRegenMPPerSptfmt[]="f";
+const char Holidaysfmt[]="nxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
 const char Itemfmt[]="nixiiiii";
 //const char ItemDisplayTemplateEntryfmt[]="nxxxxxxxxxxixxxxxxxxxxx";
 //const char ItemCondExtCostsEntryfmt[]="xiii";