`clipToStartTime: false` does not work

[VE3NEA]

The clipToStartTime: false parameter of GroundStation.Observe does not work, because the last term in the condition to walk back always evaluates to false:

if (!clipToStartTime && obs.Count > 0 && obs[0].Start == start)

This happens because obs[0].Start, computed in FindCrossingTimeWithinInterval, is between start-deltaTime and start, not exactly equal to start.

Suggested solution: replace == with <= in the if statement.