Add an option for variable names that format poorly for display purposes

[smiths]

Issue #1639 worked on improving variable names for display, but the focus there was on subscripts. We also have variables themselves that do not format properly when enclosed in $ $. This occurs when the variable name consists of more than one symbol, but to make things challenging, not every variable name of more than one character formats poorly.

Following the rule that variables should be in italic, I use $\mathit{LongVarName}$, but from previous discussion, others prefer to use a sans serif font for longer variable names.

This issue is particularly challenging because we want display automated, but there is user preference in how the long variable names are formatted. Maybe this can be a display variability that is set by the user?

One example that looks particularly bad is the equation for DD:calofCapacity, in both html and pdf (from LaTeX), respectively:

I'm going to set this issue as a future enhancement, since this is just a display issue.