title: antcall based on a condition
body: <p>This is what I am trying to achieve:</p>
  
  <p>if a property is set then call antcall target. is this doable? can someone tell me how?</p>
  
  <pre><code>&lt;condition&gt;
      &lt;isset property="some.property"&gt;
          &lt;antcall target="do.something"&gt;
      &lt;/isset&gt;
  &lt;/condition&gt;
  </code></pre>