Default color panel is taken into account with the indexes

Due to the last commit in ctkColorDialog, the default panel is not index 0,
extra panel indexes start at 1.

Libs/Widgets/Testing/Cpp/ctkColorDialogTest1.cpp

@@ -43,29 +43,32 @@ int ctkColorDialogTest1(int argc, char * argv [] )
                    &colorDialog, SLOT(setColor(QColor)));
   colorDialog.addTab(extraPanel, "Extra");
   int index = colorDialog.indexOf(extraPanel);
-  if (index != 0 ||
+  if (index != 1 ||
       extraPanel != colorDialog.widget(index) ||
       colorDialog.widget(-1) != 0)
     {
-    std::cerr << "ctkColorDialog::addTab failed" << std::endl;
+    std::cerr << "ctkColorDialog::addTab failed:" << index << std::endl;
     return EXIT_FAILURE;
     }
 
   // fake removeTab
   colorDialog.removeTab(-1);
   index = colorDialog.indexOf(extraPanel);
-  if (index != 0 ||
-      colorDialog.widget(0) != extraPanel)
+  if (index != 1 ||
+      colorDialog.widget(1) != extraPanel)
     {
-    std::cerr << "ctkColorDialog::removeTab failed" << std::endl;
+    std::cerr << "ctkColorDialog::removeTab failed:" << index << std::endl;
     return EXIT_FAILURE;
     }
 
-  // true removeTab  
+  // true removeTab
   colorDialog.removeTab(index);
   index = colorDialog.indexOf(extraPanel);
   if (index != -1 ||
-      colorDialog.widget(0) != 0)
+      // still the default tab
+      colorDialog.widget(0) == 0 ||
+      // extra panel doesn't exist anymore
+      colorDialog.widget(1) != 0)
     {
     std::cerr << "ctkColorDialog::removeTab failed" << std::endl;
     return EXIT_FAILURE;