Confusing use of `foo=0` for unused variables in options_lookup.tsv

[shorowit]

ResStock uses foo=0 when a variable does not apply in options_lookup.tsv. That is confusing because there's no way to really differentiate between a variable that is using zero vs a variable that is not being used.

Can we change those that are not used to something like foo=na? (Or simply foo=?)

[joseph-robertson]

Is this a duplicate of #1289?

[shorowit]

For example, this could cause a bug unless specifically handled when NatLabRockies/OpenStudio-HPXML#1857 is pulled in. See here for more detail.