change the way tote stacker zeroes out

[LeoSalemann]

Needs to zero at autonomous-start; not robot power-on

[Equinox-]

If you are having problems with the robot properly zeroing, or your encoder drifts during the match you can investigate adding a limit switch the marks the "zero" location of the lifter.

You can look at the 2013 version of this, here:
ShooterPitch.cpp