Infer time: validate proper handling of date wrap.

[jmMeessen]

When inferring time, the date and time should be "wrapped" when crossing the midnight boundary.

Mentioned in #66 (comment)

[rsuzuki0]

That sounds good. Please keep in mind that many existing log input files have "date +" lines so I don't want the date to advance by two days in that case when re-processed with a new version. Might it be that FLEcli only checks for the presence of "date +" to give warning/error, or increment only if that directive is missing. I think the former might be preferable.