- merged PR by Dmitriy Klabukov and expanded it a bit

- Gerber Editor - made sure that when simplification button is clicked the coordinates and vertex points field are cleared
- Gerber Editor - added a Beginner/Advanced toggle button
- Gerber Editor - added context menu to Apertures Table and also on row selection in Aperture Table, the area and vertex number fields are updated
- Excellon Editor - added a Beginner/Advanced toggle button; added context menu to Apertures Table
- Excellon Editor - fixed the Tools Table row selection handler

appGUI/GUIElements.py

@@ -1680,6 +1680,12 @@ class FCTextEdit(QtWidgets.QTextEdit):
         tcursor = self.textCursor()
         tcursor.deleteChar()
 
+    def set_value(self, txt):
+        self.setText(txt)
+
+    def get_value(self):
+        return self.toPlainText()
+
 
 class FCTextAreaRich(FCTextEdit):
     def __init__(self, parent=None):