v3.13 released

[iz]

Once get_iplayer updates the cache in any given week, it doesn't go
back to the previous week. Ordinarily that would be unnecessary, but
you can force it with the use of --refresh-limit or --cache-rebuild,
as has already been suggested. It's likely that people did their first
update this week with the old broken get_iplayer, and thus subsequent
updates with the new get_iplayer didn't go back to last week.