Improve color slider edit history

include/ui/colorinputwidget.h

@@ -25,6 +25,7 @@ public:
 signals:
     void colorChanged(QRgb color);
     void bitDepthChanged(int bits);
+    void editingFinished();
 
 private:
     Ui::ColorInputWidget *ui;

include/ui/paletteeditor.h

@@ -39,6 +39,7 @@ private:
 
     Tileset* getTileset(int paletteId);
     void refreshColorInputs();
+    void commitEditHistory();
     void commitEditHistory(int paletteId);
     void restoreWindowState();
     void closeEvent(QCloseEvent*);