Complete support for Calendar during reads/writes to apply to various type conversions

As part of CASTOR-1276, support has been added to consider timezones during database writes as well (in addition to the already existing support for timezones during reads). Unfortunately, both aditions only cover cases where a java.util.Date property is mapped to one of the java.sql.Date|Time|Timestamp classes. The current support does not cover cases where the java.util.Date instance is being converted to e.g. a numeric or String field.