- removed the import of the whole FlatCAMApp file only for the usage of GracefulException
- remove the import of FlatCAMApp and used alternate ways
- optimized the imports in some files
- moved the Bookmarksmanager and ToolDB classes into their own files
- solved some bugs that were not so visible in the Editors and HPGL parser
- in Excellon UI removed the tools table column for Offset Z and used the UI form parameter
- updated the Excellon Editor to add for each tool a 'data' dictionary
- updated all FlatCAM tools to use the new confirmation message that show if the entered value is within range or outside
- 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)
- when the Tool tab is in focus, clicking on canvas will no longer change the focus to Project tab
- Copper Thieving Tool - when creating the pattern platting mask will make a new Gerber object with it
- in Tools Database made the status bar messages show when adding/copying/deleting tools in DB
- changed all Except statements that were single to except Exception as recommended in some PEP
- renamed the Copper Fill Tool to Copper Thieving Tool as this is a more appropriate name; started to add ability for more types of copper thieving besides solid
- fixed some issues recently introduced in ParseSVG
- updated POT file