Feature request: Command-line arguments

[typingtanuki]

Thanks for the awesome tool.

I want to integrate xcalibrate in a setup tool used for setting up a new device (install packages, tweak settings, ...) but currently users have to drop into command-line to fill-in the settings.

Arguments which would be useful (with sample):

• Only listing devices: ./xcalibrate --list-devices
• Start with a specific device (based on the above list): ./xcalibrate --device "Device name or some ID"
• Start with a specific amount of calibration points: ./xcalibrate --points 12
• Output calibration data into a file: ./xcalibrate --output "some file"

[JosephSummerhays1]

@reinderien, I'd love to fix this issue if you made me a contributor and assigned it to me.

[reinderien]

@JosephSummerhays1 Let's please discuss in https://gitter.im/reinderien_xcal/Lobby