title: convert NSString to an NSArray with more than one condition
body: <p>I have a string that contains some text with periods and commas. I'd like to convert it to an NSArray based on the commas AND the periods. I use this method to separate based on one type of condition, but how do I do that with two? </p>
  
  <pre><code>componentsSeparatedByString:
  </code></pre>
  
  <p>Thanks. </p>