title: Remove duplicate module from browserify bundle
body: <p>I have a browserify bundle, let's call it <code>core.js</code>, that contains a <code>require('../module-a');</code> statement.  <code>core.js</code> is included on every page on my website.</p>
  
  <p>I have a separate bundle that is page-specific, let's call it <code>page.js</code>.  Inside <code>page.js</code>, there is a <code>require('../../some/folder/module-a');</code> statement.</p>
  
  <p>As of right now, <code>module-a</code> is duplicated in both <code>core.js</code> and <code>page.js</code>.  What I would like is to tell browserify that when <code>page.js</code> is generated, search the <code>core.js</code> bundle for <code>module-a</code> first, and use <code>module-a</code> from that bundle if it exists.</p>
  
  <p>What I don't want is to generate a <code>common.js</code> bundle that includes shared code from both <code>core.js</code> and <code>page.js</code>.  I want <code>core.js</code> to stay the same, and to simply trim down <code>page.js</code>.  I also don't want to have to manually tell the <code>page.js</code> bundle that <code>core.js</code> already contains <code>module-a</code>, I have way too many modules for that to be feasible.  I need it to be done programmatically.</p>
  
  <p>Is this possible?</p>