Added logging to the sag-tension analysis function.
Added logging to the sag-tension analysis function.

Reworked the logic so that each weathercase evaluates all cable
conditions. Validation errors for the span, weathercase, and
reloader are logged to help the user identify the problem.

OverheadTransmissionLineSoftware/SpanAnalyzer,OverheadTransmissionLineSoftware/SpanAnalyzer,OverheadTransmissionLineSoftware/SpanAnalyzer,OverheadTransmissionLineSoftware/SpanAnalyzer