title: How do I test if one array is a subset of another?
body: <p>What's the best (cleanest) way to provide this sort of logic?</p>
  
  <pre><code>var colors = ["red","white","blue"];
  
  logic(colors,["red","green"]); //false
  logic(colors,["red"]); //true
  logic(colors,["red","purple"]); //false
  logic(colors,["red","white"]); //true
  logic(colors,["red","white","blue"]); //true
  logic(colors,["red","white","blue","green"]); //false
  logic(colors,["orange"]); //false
  </code></pre>
  
  <p>Possibly using <a href="http://underscorejs.org/">underscore.js</a>?</p>