title: npm install : specify package.json?
body: <p>How can I tell npm to use another package.json when running "npm install" ? </p>
  
  <p>All I need is <code>npm install -f packages-win32.json</code> Or is there a trick or another approach to achieve the same? </p>
  
  <p>Because not all npm modules are cross-platform and I'd like to use other packages per platform.</p>