- optimized and fixed some issues in the self.on_toggle_units() method
- the Exclusion areas will have all the orange color but the color of the outline will differ according to the type of the object from where it was added (cosmetic use only as the Exclusion areas will be applied globally)
- added a first new example script and added some files to work with
- added a new parameter that will store the home folder of the FlatCAM installation so we can access the example folder
- in PreferencesUI.PreferencesUIManager class I removed the need to pass reference to the App class since it this was available through the 'ui' parameter
- some fixes due to recent refactoring
- minor bugs fixed (not so visible)
- promoted some methods to be static
- set the default layout on first run to the 'minimal' value