Extended support for Joda Time (LocalDate class).

Please use the [`LocalDate(Object, DateTimeZone) constructor`](http://joda-time.sourceforge.net/apidocs/org/joda/time/LocalDate.html#LocalDate%28java.lang.Object,%20org.joda.time.DateTimeZone%29) with [`DateTimeZone.UTC`](http://joda-time.sourceforge.net/apidocs/org/joda/time/DateTimeZone.html#UTC) to be consistent with `DateTimeParam`.