- refactored the imports in the Plugins, moved almost all imports in the AppTool file

- fixed a number of issues, mostly leftovers from moving the UI of a Plugin in its own class
- fixed some bugs in the Punch Gerber plugin
- fixed some bugs where the 'pool' parameter was not passed when creating shapes collections (in 3D graphic mode); I wonder how it worked until now
- added a new feature in the Isolation Plugin: now for all the isolation Geometry objects this plugin can do a supplementary simplification of the geometry using the tolerance parameter defined in the General Parameters. This should lead to a reduced number of tool lifts when doing corners

appObjects/AppObjectTemplate.py

@@ -94,7 +94,7 @@ class FlatCAMObj(QtCore.QObject):
 
         if self.app.use_3d_engine:
             self.shapes = self.app.plotcanvas.new_shape_group()
-            self.mark_shapes = ShapeCollection(parent=self.app.plotcanvas.view.scene, layers=1)
+            self.mark_shapes = ShapeCollection(parent=self.app.plotcanvas.view.scene, layers=1, pool=self.app.pool)
         else:
             self.shapes = ShapeCollectionLegacy(obj=self, app=self.app, name=name)
             self.mark_shapes = ShapeCollectionLegacy(obj=self, app=self.app, name=name + "_mark_shapes")