title: Overwrite less mixin
body: <p>I wish to remove <code>border radius</code> from all the elements in Bootstrap. So I created <code>custom-mixins.less</code> and placed following lines in it, hopping that it would overwrite the original <code>.border-radius</code> mixin but didn't.</p>
  
  <pre><code>// Border Radius
  .border-radius(@radius) {      
  }
  </code></pre>
  
  <p>So I tried following lines as an alternative which actually worked.</p>
  
  <pre><code>// Border Radius
  .border-radius(@radius) {
    @radius : 0px;
    -webkit-border-radius: @radius;
       -moz-border-radius: @radius;
            border-radius: @radius;
  }
  </code></pre>
  
  <p>I tried some mixins at <code>http://less2css.org</code>. It seems that less instead of overwriting the mixins, appends all the properties from later mixin to the original one. Is there any cleaner and easier solution to this????</p>