add warning on crazy model/data values, and print min/max

[o-smirnov]

@KshitijT ran into a crazy MODEL_DATA column. He's not the first one and he won't be the last, and it's not a CubiCal problem per se, but the resulting behaviour is "why is my solver acting funny", and it can be tricky to diagnose quickly.

Suggest adding a debug-print statement (at level 1 or 2) to the solver with the min/max/mean data and model amplitudes. That way crazy inputs will be easy to spot.

We could even add a warning message. But what's the threshold for "crazy" data?