title: Replay a Scrapy spider on stored data
body: <p>I have started using <a href="http://scrapy.org/" rel="noreferrer">Scrapy</a> to scrape a few websites. If I later add a new field to my model or change my parsing functions, I'd like to be able to "replay" the downloaded raw data offline to scrape it again. It looks like Scrapy had the ability to store raw data in a replay file at one point:</p>
  
  <p><a href="http://dev.scrapy.org/browser/scrapy/trunk/scrapy/command/commands/replay.py?rev=168" rel="noreferrer">http://dev.scrapy.org/browser/scrapy/trunk/scrapy/command/commands/replay.py?rev=168</a></p>
  
  <p>But this functionality seems to have been removed in the current version of Scrapy. Is there another way to achieve this?</p>