title: Create Ransack object without querying DB
body: <p>I'd like to be able to create a Ransack::Search object to be passed into a search_form_for, but the initial creation of the search object queries the database, wich I don't want.</p>
  
  <p>I want to show an initial blank form with Ransack::Search options to search, without calling the database.</p>
  
  <p>How can I do that ?</p>
  
  <p>thanks,</p>
  
  <p>regards</p>