templates/queries-index-mysql.tpl.html, templates/queries-index-sqlite.tpl.html: Enhanced the query that finds the next free slot (query_next_available_episode). Also made it compute the days to the slot from the current day. The query returns data for calling Date::Calc to compute the number of days, but this calculation is no longer necessary. Next release will remove this. templates/content-index.tpl.html: The number of days to the next free slot is reported here. The original Date::Calc computation which did this is no longer needed and has been removed since the query (query_next_available_episode) does it.