GUI-Action: Animation - Change Unit Turn Speed -> Set it to 0. Works perfectly.
Jass: call SetUnitTurnSpeedBJ( unit, 0.00 )
Have to test what influence this has on attacks. But the unit can only run in a straight line for now. I'll collect my findings below.
Attacking is still possible in a limited angle. Don't know how it is determined though.
Art - Propulsion Window has some interesting effects. If you set it to 90° then the unit will not do anything when ordered to go behind itself, but move forward when ordered to somewhere in front of it. Similarly, if it's 180° the unit will move forward no matter where you order it to go, which interacts in a funny way with the wc3 pathing
(the engine doesn't consider stuff in front of you an obstacle because you should turn around first, thus you start moving. But since you don't turn around, you start moving through stuff in front of you).
The turnspeed isn't exactly 0, but it's close. You'll need 2 minutes to turn 180° i believe.
Also, reporting for move to Programming.