title: Rails Engine - Gems dependencies, how to load them into the application?
body: <p>I'm doing an engine here, it works alright in stand alone.</p>
  
  <p>When I transform it into a gem, and load it inside another application, I get a lot of undefined errors, coming from my engine gem's dependecies.</p>
  
  <p>Here is the gemspec:</p>
  
  <pre><code>s.add_dependency('paperclip')
  s.add_dependency('jquery-rails')
  s.add_dependency('rails3-jquery-autocomplete')
  s.add_dependency('remotipart')
  s.add_dependency('cancan')
  </code></pre>
  
  <p>In the application, when I do a bundle install, it lists all these dependencies, but as i run the application I receive a lot of undefined methods errors (has_attachment from paperclip for example). It seems that the application doesn't load the engines dependencies.
  Is this the default behavior? Can I change it?
  Same thing happened with a plugin inside the engine.</p>
  
  <p>If I insert by hand those gems, in the application Gemfile, all works...</p>