Fixed service unavailable issue for large blogs

I wanted to test a large blog to help determine any unknown errors.
So I thought I would try http://googleblog.blogspot.co.uk/

There are almost 3000 pages on this blog.
I'd originally setup the feeds to be pulled in 20 at a time (like the
current tumblr importer). This yielded 147 feed requests

The issue I got was always around batch number 68.
It seemed to get back a service unavailable message but if I went to the
feed url manually through the browser it returned the correct data.

[batch 68 link](
http://googleblog.blogspot.co.uk//feeds/posts/default?alt=json&start-index=1361&max-results=20)

When I peeked at the remaining feed results in the callback I could see
that all the other results beyond batch 68 were containing correct data.
It was always one feed that had a service unavailable (around 67,68,69)

So I realised that batches of 20 was causing blogger to intermittently
deny requests.

So the fix was to add a itemsPerRequest config setting and set it to 50
as default which allows me to get all the posts from
http://googleblog.blogspot.co.uk/ without an error.
Removed console logging bits