title: Moment.js first day of the week incorrect
body: <p>I'm working with Moment.js for my first time. I tried to retrieve the date of the first day of the week, and in Europe this is normally Monday. Whatever I do, I get Sunday as result of the first day of the week. </p>
  
  <p>I tried to set-up different languages (local or globally), but to no avail. I use the langs.min.js file from the <a href="https://github.com/timrwood/moment/tree/develop/min">moment.js github page</a>. The language file of "en-gb" and <a href="https://github.com/timrwood/moment/blob/develop/lang/fr.js">"fr"</a> has the line of code:</p>
  
  <pre><code>dow : 1, // Monday is the first day of the week.
  </code></pre>
  
  <p>So I would get the date of monday when I ask for the first day of the week right? I keep getting Sunday as output.</p>
  
  <pre><code>// Create moment object
  var localLang = moment();
  
  // Set language to french
  localLang.lang('fr');
  
  // Test language
  localLang.lang(); // Output: fr
  
  // Retrieve first day of the week and format it
  var dow = localLang.startOf('week').format('dddd DD-MM-YYYY'); // Output: dimanche 14-04-2013
  </code></pre>
  
  <p>Dimanche is french for Sunday.. As you see, moment.js can use the language file succesfully but doesn't use the day of the week configuration</p>
  
  <p>JSfiddle with moment.js and langs.js to test: 
  <a href="http://jsfiddle.net/JesseDobbelaere/pCwb5">JSFiddle</a></p>
  
  <p>edit: 
  I can get the date of Monday instead of Sunday with <code>day(1)</code> instead of <code>startOf('week')</code>. But using <code>day(0)</code>I still get Sunday as a result. Why isn't monday the first day of the week, as configured in the language files.</p>