Comment 97 for bug 1292398

Same thing is for Unity
I'm using
Ubuntu 16.04 (upgraded from 12.04->14.04->16.04)
lightdm 1.18.1
Unity 7.4.0

When system is booting first look at login window is good, then it rewrites a screen and makes monitors changed to wrong order. Changing monitors to right order after login via system settings helps only for the current session untill reboot

Needs fix