#1379 Questionable default for Unsteady Flow: timestep display interval min, max

[Scott]

This is more of a bad default setting than it is a bug. I'm writing it up as a bug so we're more likely to discuss and change it before the release of 2.6.0.

In our unsteady flow settings, our timestep display interval is set for the range -100:1. In my usage, I typically use the setting as -1:1 to show a single particle moving through time. -100:1 shows very long trajectories and I'm doubtful that this is desired by most users, but who knows.

Should the default be kept as is, or can we set it to the range -1:1?