title: Why doesn't Nutch seem to know about "Last-Modified"?
body: <p>I setup Nutch with a db.fetch.interval.default of 60000 so that I can crawl every day.  If I don't, it won't even look at my site when I crawl the next day.  But when I do crawl the next day, every page that it fetched yesterday gets fetched with a 200 response code, indicating that it's not using the previous day's date in the "If-Modified-Since".  Shouldn't it skip fetching pages that haven't changed?  Is there a way to make it do that?  I noticed a ProtocolStatus.NOT_MODIFIED in Fetcher.java, so I think it should be able to do this, shouldn't it? </p>
  
  <p>By the way, this is cut and pasted from conf/nutch-default.xml from the current trunk:</p>
  
  <pre><code>&lt;!-- web db properties --&gt;
  
  &lt;property&gt;
    &lt;name&gt;db.default.fetch.interval&lt;/name&gt;
    &lt;value&gt;30&lt;/value&gt;
    &lt;description&gt;(DEPRECATED) The default number of days between re-fetches of a page.
    &lt;/description&gt;
  &lt;/property&gt;
  
  &lt;property&gt;
    &lt;name&gt;db.fetch.interval.default&lt;/name&gt;
    &lt;value&gt;2592000&lt;/value&gt;
    &lt;description&gt;The default number of seconds between re-fetches of a page (30 days).
    &lt;/description&gt;
  &lt;/property&gt;
  </code></pre>