odom == pose when uncertain_odom=false

[PetervDooren]

previously this was not a problem as the robot started at 0,0,0. However after #63 the robot will often start in the middle of the map.

Now, however it may make more sense to just disable the drift on the odom. while still having it start at 0,0,0.
downside may be that students dont have a good way of getting the pose while they are working on localization