title: How does the "replace" property work with composer?
body: <p>So how does the "<a href="http://getcomposer.org/doc/04-schema.md#replace">replace</a>" property work with <a href="http://getcomposer.org/">composer</a>? I have read the composer document but still not understand it. Searching for more info hasn't answered my questions.</p>
  
  <p>When I look at the composer.json file on <a href="https://github.com/laravel/framework/blob/master/composer.json">Laravel/Framework</a> on github. I can't see how replace will work. Can someone explain to me how this works? And what the variable "self.version" will equal to?</p>