min & max don't work correctly for some history fields

[escomp]

min & max don't work correctly for some history fields

[billsacks]

Let's discuss how to proceed here: We could

1. close this as wontfix

2. fix it according to the suggestions and put similar changes in other parts of the code without necessarily testing all places (quick, but risky)

3. fix it according to the suggestions and put similar changes in other parts of the code, with sufficient testing (safe, but longer)

4. refactor the code to eliminate duplication, fix it, and do testing (less testing required than 3) (longest implementation time, but less testing burden than (3))

[billsacks]

From discussion: let's do (2) but do just limited testing to ensure that answers don't change for min & max fields that don't go between spval and real values.