Add options to skip present-date values in dateJoiner refinery

When importing Excel (XLSX) files, columns with blank date values can be auto-set by Excel to be the current date. When used with the dateJoiner this can result in incorrect date ranges.

Since current date values _can_ be correct and desirable, we need options (ignorePresentDayStartDates and ignorePresentDayEndDates) to explicitly ignore them in cases where they are clearly in error.