- fixed an issue in old default file detection and in saving the factory defaults file

- in Preferences window removed the Import/Export Preferences buttons because they are redundant with the entries in the File -> Menu -> Backup. and added a button to Restore Defaults
- when in Basic mode the Tool type of the tool in the Geometry UI Tool Table after isolating a Gerber object is automatically selected as 'C1'
- let the multiprocessing Pool have as many processes as needed
- added a new Preferences setting allowing a custom mouse line width (to make it thicker or thinner)

flatcamGUI/PlotCanvasLegacy.py

@@ -375,16 +375,19 @@ class PlotCanvasLegacy(QtCore.QObject):
         pass
         # log.debug("Cache updated the screen!")
 
-    def new_cursor(self, axes=None, big=None):
+    def new_cursor(self, axes=None, big=None, color=None):
         # if axes is None:
         #     c = MplCursor(axes=self.axes, color='black', linewidth=1)
         # else:
         #     c = MplCursor(axes=axes, color='black', linewidth=1)
 
-        if self.app.defaults['global_theme'] == 'white':
-            color = '#000000'
+        if color:
+            color = color
         else:
-            color = '#FFFFFF'
+            if self.app.defaults['global_theme'] == 'white':
+                color = '#000000'
+            else:
+                color = '#FFFFFF'
 
         if big is True:
             self.big_cursor = True
@@ -398,7 +401,7 @@ class PlotCanvasLegacy(QtCore.QObject):
 
         return c
 
-    def draw_cursor(self, x_pos, y_pos):
+    def draw_cursor(self, x_pos, y_pos, color=None):
         """
         Draw a cursor at the mouse grid snapped position
 
@@ -408,10 +411,13 @@ class PlotCanvasLegacy(QtCore.QObject):
         """
         # there is no point in drawing mouse cursor when panning as it jumps in a confusing way
         if self.app.app_cursor.enabled is True and self.panning is False:
-            if self.app.defaults['global_theme'] == 'white':
-                color = '#000000'
+            if color:
+                color = color
             else:
-                color = '#FFFFFF'
+                if self.app.defaults['global_theme'] == 'white':
+                    color = '#000000'
+                else:
+                    color = '#FFFFFF'
 
             if self.big_cursor is False:
                 try:
@@ -421,10 +427,11 @@ class PlotCanvasLegacy(QtCore.QObject):
                     # The size of the cursor is multiplied by 1.65 because that value made the cursor similar with the
                     # one in the OpenGL(3D) graphic engine
                     pointer_size = int(float(self.app.defaults["global_cursor_size"] ) * 1.65)
-                    elements = self.axes.plot(x, y, '+', color=color, ms=pointer_size, mew=1, animated=True)
+                    elements = self.axes.plot(x, y, '+', color=color, ms=pointer_size,
+                                              mew=self.app.defaults["global_cursor_width"], animated=True)
                     for el in elements:
                         self.axes.draw_artist(el)
-                except Exception as e:
+                except Exception:
                     # this happen at app initialization since self.app.geo_editor does not exist yet
                     # I could reshuffle the object instantiating order but what's the point?
                     # I could crash something else and that's pythonic, too