Improved Time Functions

[JBaity]

Request improved handling of time values:

• Add rounding (up, down , and nearest) to the minute, x minutes, or hour.
• Add a default time hierarchy so that visuals can be drilled up and down from second to minute to quarter-hour to hour.
• Add 24-hour clock as a formatting option in the modeling options.
• Improve scatter plots that use time on the X axis such that it sorts properly, even when a legend is applied (currently, it inconsistently sorts by legend first, then by the selected sort criteria).