- fix error in plotting Excellon when toggling units

- FlatCAM editors now are separated each in it's own file
- fixed TextTool in Geometry Editor so it will open the notebook on activation and close it after finishing text adding
- started to work on a Gerber Editor

FlatCAMObj.py

@@ -2640,7 +2640,7 @@ class FlatCAMExcellon(FlatCAMObj, Excellon):
     #     except TypeError:  # Element is not iterable...
     #         self.add_shape(shape=element, color=color, visible=visible, layer=0)
 
-    def plot(self):
+    def plot(self, kind=None):
 
         # Does all the required setup and returns False
         # if the 'ptint' option is set to False.