feedreader.parser.from_url chokes on Temporary Redirects

[jenner]

The from_url() function only checks for HTTP status codes 200, 301 and 302 while there's also 307 (see http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.8), which is (alas) widely used by a couple of popular rss sites.