Remove old fit parameters from LoopHelixInfo when new cuts are defined

[AndrewEdmonds11]

We have added back in d0, tanDip, and maxr into the demlhi branch so that people can continue to use them while we define more physics-focused variables (e.g. does the track extrapolate back to hit the OPA). Once those variables are ready (or we have new cuts using LoopHelix parameters), we should remove the placeholders so that we don't get confused