Core/Groups: Move all function definition from .h to .cpp

Core/Groups: Remove Group.h dependency from any .h file

--HG--
branch : trunk

src/server/game/Chat/Commands/Level1.cpp

@@ -34,6 +34,7 @@
 #include "CellImpl.h"
 #include "InstanceSaveMgr.h"
 #include "Util.h"
+#include "Group.h"
 
 #ifdef _DEBUG_VMAPS
 #include "VMapFactory.h"

src/server/game/Chat/Commands/Level3.cpp

@@ -60,6 +60,7 @@
 #include "LFGMgr.h"
 #include "CreatureTextMgr.h"
 #include "SmartAI.h"
+#include "Group.h"
 
 bool ChatHandler::HandleMaxSkillCommand(const char* /*args*/)
 {