Variables have different names in history vs. restart

Reduce potential confusion by naming variables the same in history and restart.

How to minimize backwards compatibility issues?

This issue was raised while @klindsay28 and I were working on the Newton-Krylov spin-up tool for the ctsm. Keith is adapting the tool to handle differing variable names between history and restarts, so we do not consider this issue a blocker.

@wwieder pls add anything I may have missed...