Core/Dungeon Finder: Code cleanup and minor optimizations

- Extend LfgState to keep control of the state of group and players using LFG
- Move scripts to its own class and initialize only if Dungeon finder is enabled
- Updated comments to doxygen format
- Use constructor initialization list
- All variables are declared in the inner most scope
- Fix some mem leaks
- Remove no longer needed code (Cleaner)
- Normalize handler function names

--HG--
branch : trunk

src/server/game/Scripting/ScriptLoader.cpp

@@ -76,7 +76,6 @@ void AddSC_npc_innkeeper();
 void AddSC_npcs_special();
 void AddSC_npc_taxi();
 void AddSC_achievement_scripts();
-void AddSC_dungeon_finder();
 
 //eastern kingdoms
 void AddSC_alterac_valley();                 //Alterac Valley
@@ -664,7 +663,6 @@ void AddWorldScripts()
     AddSC_npc_taxi();
     AddSC_achievement_scripts();
     AddSC_chat_log();
-    AddSC_dungeon_finder();
 #endif
 }