- updated all the FlatCAM Tools and the Gerber UI FCComboBoxes to update the box value with the latest object loaded in the App

- some fixes in the NCC Tool
- modified some strings

flatcamTools/ToolInvertGerber.py

@@ -66,7 +66,8 @@ class ToolInvertGerber(FlatCAMTool):
         self.gerber_combo = FCComboBox()
         self.gerber_combo.setModel(self.app.collection)
         self.gerber_combo.setRootModelIndex(self.app.collection.index(0, 0, QtCore.QModelIndex()))
-        self.gerber_combo.set_last = True
+        self.gerber_combo.is_last = True
+        self.gerber_combo.obj_type = "Gerber"
 
         self.gerber_label = QtWidgets.QLabel('<b>%s:</b>' % _("GERBER"))
         self.gerber_label.setToolTip(