Utility functions to convert between Basic Date type
and the representations of Date and Time in UNO, namely:
 - com.sun.star.util.Date
 - com.sun.star.util.Time
 - com.sun.star.util.DateTime

Name of new functions:
 - CDateToUnoDate
 - CDateFromUnoDate
 - CDateToUnoTime
 - CDateFromUnoTime
 - CDateToUnoDateTime
 - CDateFromUnoDateTime

Change-Id: I2b971df20df1c0351d071023e042169b548894f1
Reviewed-on: https://gerrit.libreoffice.org/5897Reviewed-by: Noel Power <noel.power@suse.com>
Tested-by: Noel Power <noel.power@suse.com>