* Enhance TimeValue.toString() to allow specifying fractional values.
This enhances the `TimeValue` class to allow specifying the number of
truncated fractional decimals when calling `toString()`. The default
remains 1, however, more (or less, such as 0) can be specified to change
the output.
This commit also re-organizes some things in `TimeValue` such as putting
all the class variables near the top of the class, and moving the
constructors to the first methods in the class, in order to follow the
structure of our other code.
* Rename `toString(...)` to `toHumanReadableString(...)`