New case selector for Calc that matches a value inside a range

[rlwhitcomb]

I want to select a block if the value is > 0.10 and < 0.20. There is no way to do that currently. It could be an extension of "compareOp expr" like this: compareOp expr '&&' compareOp expr

[rlwhitcomb]

Leaving version number, version reference, extensive tests (with canon changes) , and updates to help page to finish.