title: Renaming uploaded files with Carrierwave
body: <p>I'm using Carrierwave to upload files, and I have it working.</p>
  
  <p>My issue is attempting to change the name of the uploaded file.</p>
  
  <p>In the generated uploader.rb there is a method I think I should be using </p>
  
  <pre><code>def filename
     "something.jpg" if original_filename
     basename = "what"+orginal_filename if original_filename, works
     basename = (0...8).map{65.+(rand(25)).chr}.join if original_filename  # will create a random name for each version, e.g. the orginal, the thumb, and the filename in the db, useless
   end
  </code></pre>
  
  <p>I can't seem to access items like 'extension' or 'content_type' in sanitized_file.rb, so this is a bit beyond my current skill level right now.</p>
  
  <p>Any suggestions or exercises for doing this, i.e. generate filename for an uploaded file that works as well as the carrierwave default (do nothing, but does carry on to each version)? Seems like it should be simple enough but I've stumbled over this.</p>