Copy/paste model values to system clipboard

Previously they were copy/pasted internally, and not visible across LMMS
instances.

include/AutomatableModel.h

@@ -96,11 +96,6 @@ public:
 	virtual ~AutomatableModel();
 
 
-	static float copiedValue()
-	{
-		return s_copiedValue;
-	}
-
 	bool isAutomated() const;
 	bool isAutomatedOrControlled() const
 	{
@@ -288,8 +283,6 @@ public:
 
 public slots:
 	virtual void reset();
-	virtual void copyValue();
-	virtual void pasteValue();
 	void unlinkControllerConnection();
 
 
@@ -352,8 +345,6 @@ private:
 	ControllerConnection* m_controllerConnection;
 
 
-	static float s_copiedValue;
-
 	ValueBuffer m_valueBuffer;
 	long m_lastUpdatedPeriod;
 	static long s_periodCounter;

include/AutomatableModelView.h

@@ -75,7 +75,6 @@ protected:
 
 	QString m_description;
 	QString m_unit;
-
 } ;
 
 
@@ -94,6 +93,11 @@ public slots:
 	void unlinkAllModels();
 	void removeSongGlobalAutomation();
 
+private slots:
+	/// Copy the model's value to the clipboard.
+	void copyToClipboard();
+	/// Paste the model's value from the clipboard.
+	void pasteFromClipboard();
 
 protected:
 	AutomatableModelView* m_amv;