Steps: add a pointer to the associated Song. not used yet.

src/Steps.cpp

@@ -42,7 +42,7 @@ static const char *DisplayBPMNames[] =
 XToString( DisplayBPM );
 LuaXType( DisplayBPM );
 
-Steps::Steps(): m_StepsType(StepsType_Invalid), 
+Steps::Steps(): m_StepsType(StepsType_Invalid), m_pSong(NULL),
 	parent(NULL), m_pNoteData(new NoteData), m_bNoteDataIsFilled(false), 
 	m_sNoteDataCompressed(""), m_sFilename(""), m_bSavedToDisk(false), 
 	m_LoadedFromProfile(ProfileSlot_Invalid), m_iHash(0),

src/Steps.h

@@ -171,6 +171,8 @@ public:
 	void PushSelf( lua_State *L );
 
 	StepsType			m_StepsType;
+	/** @brief The Song these Steps are associated with */
+	Song				*m_pSong;
 
 	CachedObject<Steps> m_CachedObject;