This program is not working correctly on kernel versions 4.x on Intel. It might work on other GPUs but there is no such guarantee.
Custom resolution scaling
xrandr
This program currently reads from ~/rescfg 4 numbers, namely the width and height of the native resolution and that of the scaled resolution.
customresolution --switch sends a SIGUSR1 signal to all daemons it could get (should normally be only the one for the currently active screen; doesn't work well with multiple sessions of the same user or if running as root)
customresolution without arguments kills all other instances of the daemon, then it renames itself into --resdaemon
customresolution --reload sends a SIGUSR2 signal to all daemons to reread the configuration file ~/rescfg