nixos/displaylink: write out required xorg.conf fragment
nixos/displaylink: write out required xorg.conf fragment

Invoke xrandr to actually connect the device.

Additionally, we let systemd create the logs directory and use our module loader
instead of handling it manually.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs