v8.4 Important fixes

• Implement sub-pixel rendering (if your system supports it this will improve the quality of text rendering)
• Implement support for saving/loading statistics on exit/launch (#25)
• Update global keyboard/mouse listener library
  • Fixes character combinations not working (e.g. e + " = ë)
  • Resolves some rare freezes on OSX
• Fix the program not working under Java 16 (#30)
• Fix the border offset not properly applying to the fill color
• Fix not being able to add the ESC key due to it closing the dialog
• Enable the 'save config' button by default