- fixed Tcl Command CncJob

- fixed crash due of Properties Tool trying to have a convex hull area on FlatCAMCNCJob objects which is not possible due of their nature
- modified Tcl Command SubtractRectangle
- fixed and modernized the Tcl Command Scale to be able to scale on X axis or on Y axis or on both and having as scale reference either the (0, 0) point or the minimum point of the bounding box or the center of the bounding box.
- fixed and modernized the Tcl Command Skew

tclCommands/TclCommandWriteGCode.py

@@ -37,7 +37,7 @@ class TclCommandWriteGCode(TclCommandSignaled):
             ('preamble', 'Text to append at the beginning.'),
             ('postamble', 'Text to append at the end.')
         ]),
-        'examples': []
+        'examples': ["write_gcode name c:\\\\gcode_repo"]
     }
 
     def execute(self, args, unnamed_args):