Adding per curve default curve capabilities, used in the Color Toning tool as of now. See issue 2014

rtgui/myflatcurve.cc

@@ -1448,9 +1448,15 @@ void MyFlatCurve::setType (FlatCurveType t) {
     setDirty(true);
 }
 
-void MyFlatCurve::reset(double identityValue) {
+void MyFlatCurve::reset(const std::vector<double> &resetCurve, double identityValue) {
     calcDimensions();
 
+    // If a resetCurve exist (non empty)
+    if (!resetCurve.empty()) {
+        setPoints(resetCurve);
+        return;
+    }
+
     switch (curve.type) {
     case  FCT_MinMaxCPoints :
         defaultCurve(identityValue);