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/scripts/World/chat_log.cpp

@@ -18,6 +18,7 @@
 #include "ScriptPCH.h"
 #include "Channel.h"
 #include "Guild.h"
+#include "Group.h"
 
 class ChatLogScript : public PlayerScript
 {

src/server/scripts/World/dungeon_finder.cpp

@@ -21,6 +21,7 @@
 
 #include "ScriptPCH.h"
 #include "LFGMgr.h"
+#include "Group.h"
 
 class DungeonFinderScript: public GroupScript, PlayerScript
 {