Don't plot hours/minutes/seconds for models with larger timesteps

[Bob Lounsbury]

On the MODSIM Output Display x-axis don't plot 'Date 00:00:00' just 'Date' for timesteps greater than hourly. It's wasting precious screen real estate. Plot the same as was done in version 8.1.

[Bob Lounsbury]

Closes #19, closes #20. Fixed unhandled exception in model with undefined Mid-Date in table. Changed MODSIM Output Display to not use 00:00:00 in the x-axis date for timesteps greater than hourly.

→ <<cset 0c9f867cf0cd>>

[Bob Lounsbury]

I should mention this was brought up by Enrique, I agreed it should be changed as including 00:00:00 is rather pointless in the plot for the typical daily/monthly model.