Support macOS Big Sur

• Support macOS Big Sur
• Don't require to disable SIP on Catalina and Big Sur, as macOS now supports overriding display properties in /Library/Displays/Contents/Resources/Overrides
• Add icon chooser with possibility to add custom display icon
  
• Add ability to change the flags, so that Displays prefpane can use Retina style
  
• Preserve all existing properties, so that Apple displays are not corrupted by customisation

Settings restore functionality hasn't been reviewed and tested, so it's disabled. It will be restored in the next update.

2.3.3

• Improve command line argument handling #14 (thanks @rread)
• Update values for added resolutions without pressing Enter
• Recognize that disabled (Apple Internal) for SIP status still means disabled
• Fix possible issues with pointers when adding resolutions

Support macOS 10.15 Catalina

On macOS Catalina and higher RDM will execute mount -uw / before saving the override plist to remount system volume for writing. As there is no way to remount it back to read-only, it's recommended to reboot immediately after applying changes.

Display mirroring option

Now you can mirror displays without going to System Preferences.

Update: fix plist saving.

Version 2.3 with resolution plist editor

In this release scaled resolution plist editor is introduced. You no more need to manually generate the override plist using https://comsysto.github.io/Display-Override-PropertyList-File-Parser-and-Generator-with-HiDPI-Support-For-Scaled-Resolutions/. SIP should be disabled to edit resolutions, new resolutions are available after reboot.