added level<->label methods

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@179 0778d3d1-df1d-0410-868b-ea421aaaa00d

include/level_object.h

@@ -50,6 +50,9 @@ public:
 
 	virtual void setLevel( int _level ) = 0;
 
+	virtual QString levelToLabel( int _level ) = 0;
+	virtual int labelToLevel( QString _label ) = 0;
+
 
 protected:
 	int m_minLevel;