stackexchange-favs-to-pinboard

Don't know if somehting changed or this was just always semi-broken
(probable), but noticed today it wasn't adding any new favs when I knew
for a fact I had some; Perhaps, also, I have a lot more favs than when I
first wrote this.

Previously this assumed that the response returned all favs for a site
whereas actually by default it returns just 30. Perhaps by luck I'd been
picking up new ones because of using "sort=activity"; a strange choice
on it's own as if I'd used "sort=added" and run this fairly regularly
perhaps I'd never had noticed any issue? Anyway, now it does the correct
thing which is pull 100 at a time and look for the has_more parameter in
what is returned so it knows whether it needs to fetch another page.

This does mean get_favs now returns an array of items (makes more sense)
than the actual encompassing response as it used to. Leaf check-in: 09c6947036 user: base@atomicules.co.uk tags: master, trunk

Since have to (well should do, to be nice) rate limit quite a lot it can
be slow to add new bookmarks to Pinboard when we are checking Pinboard
for every single StackExchange fav. Keep a local cache of items already
added to Pinboard.

Some things I have to do (note to self):

- Check for success on Pinboard add before adding to cache
- Consider removing bookmarks on Pinboard for unfaved StackExchange
items? Leaf check-in: 29383c0dea user: base@atomicules.co.uk tags: origin/master, trunk