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/Miscellaneous/SharedDefines.h

@@ -2874,4 +2874,16 @@ enum RemoveMethod
     GROUP_REMOVEMETHOD_LEAVE   = 2,
 };
 
+enum LfgState
+{
+    LFG_STATE_NONE,                                        // Not using LFG / LFR
+    LFG_STATE_ROLECHECK,                                   // Rolecheck active
+    LFG_STATE_QUEUED,                                      // Queued
+    LFG_STATE_PROPOSAL,                                    // Proposal active
+    LFG_STATE_BOOT,                                        // Vote kick active
+    LFG_STATE_DUNGEON,                                     // In LFG Group, in a Dungeon
+    LFG_STATE_FINISHED_DUNGEON,                            // In LFG Group, in a finished Dungeon
+    LFG_STATE_RAIDBROWSER,                                 // Using Raid finder
+};
+
 #endif