Shrink validity range to "engineering valid" values

[grumpyinca]

• Experiment with reduced validity range in initialState.
• Develop & evaluate test cases based on the new validity limits

This issue provides a branch in which to experiment with validity limits and develop an understanding of unintended consequences. It may not go beyond a limited trial with the initial state for compression spring in US units.

The branch will be based on master-4.3.3. Changes intended for production release would likely be v5.0 or later.

[1fifoto]

Need to add to test case expect some way to display failing symbol table variable name

[grumpyinca]

Consider changing ValidMin on FS_2 to be 1.0 (or perhaps just slightly less).