Further reduction of include dependencies

rtgui/mydiagonalcurve.h

@@ -27,18 +27,8 @@
 #include "mycurve.h"
 
 #include "../rtengine/LUT.h"
+#include "../rtengine/diagonalcurvetypes.h"
 
-// For compatibility and simplicity reason, order shouldn't change, and must be identical to the order specified in the curveType widget
-enum DiagonalCurveType {
-    DCT_Empty = -1,     // Also used for identity curves
-    DCT_Linear,         // 0
-    DCT_Spline,         // 1
-    DCT_Parametric,     // 2
-    DCT_NURBS,          // 3
-    DCT_CatumullRom,    // 4
-    // Insert new curve type above this line
-    DCT_Unchanged       // Must remain the last of the enum
-};
 
 class DiagonalCurveDescr
 {