configure_displays should be ran here:

* On resume from suspend
* On key press from window manager (shortcut) -- currently $mod+p in ~/.i3/config
* On login startup -- currently ~/.i3/startup

The simple /etc/pm/sleep.d/50_configure-displays script:
----
#!/bin/sh
# Configure displays on resume and thaw

case "$1" in
	resume|thaw)
		if [ -f /usr/local/bin/dispcfg ]; then
			user=$(ps -fp $((pgrep -x i3 && pgrep -x xfwm4) | tail -1) | awk '{ print $1 }' | tail -1)
			export DISPLAY=:0
			export XAUTHORITY=/home/$user/.Xauthority
			/usr/local/bin/dispcfg
		fi
		;;
esac
----