Remove some caching.

Reduce drudgereport URL caching to the last 150 from 500 (probably fine)

The RSS feed reader keeps track of what it's seen already, which saves 1500
cache entries... may be necessary to bring this back though, depending on
whether identical stories get posted to multiple feeds.
Another get_http fix

Might want to retrieve the content of some non-200 responses.
URL plugin fix for error pages and missing titles.