Renamed "Series" to "Sequence(s)".
Add support for calendar date as 'availability date" on sequence list.
Added support for displaying posts/pages for the sequence in the correct order when specifying either "# of days" or an absolute date for the "Delay" value.
TODO: Fix "Post in this series" sort order (repspect the settings) for "Date" or "Delay" column in metabox.