title: uri_to_assoc issue
body: <p><p>This is my code</p><code>
  $default&nbsp;=&nbsp;array('location',&nbsp;'id',&nbsp;'page');<br>$url_info&nbsp;=&nbsp;$this-&gt;uri-&gt;uri_to_assoc(3,&nbsp;$default);&nbsp;<br>var_dump($url_info);&nbsp;
  
  </code></p>
  
  <p>If my url is</p>
  
  <code>
  http://localhost/cidbg/test/uritest/location/india/page/8/id/58&nbsp;
  
  </code>
  
  <p><p>Then my $url_info is ok.</p><code>
  array<br>&nbsp;&nbsp;'location'&nbsp;=&gt;&nbsp;string&nbsp;'india'&nbsp;(length=5)<br>&nbsp;&nbsp;'page'&nbsp;=&gt;&nbsp;string&nbsp;'8'&nbsp;(length=1)<br>&nbsp;&nbsp;'id'&nbsp;=&gt;&nbsp;string&nbsp;'58'&nbsp;(length=2)&nbsp;
  
  </code></p>
  
  <p> <br>
   <br>
  But when my url is</p>
  
  <code>
  http://localhost/cidbg/test/uritest/location/india/page//id/58&nbsp;
  
  </code>
  
  <p><p>Then my $url_info is like this.</p><code>
  array<br>&nbsp;&nbsp;'location'&nbsp;=&gt;&nbsp;string&nbsp;'india'&nbsp;(length=5)<br>&nbsp;&nbsp;'page'&nbsp;=&gt;&nbsp;string&nbsp;'id'&nbsp;(length=2)<br>&nbsp;&nbsp;58&nbsp;=&gt;&nbsp;boolean&nbsp;false<br>&nbsp;&nbsp;'id'&nbsp;=&gt;&nbsp;boolean&nbsp;false&nbsp;
  
  </code></p>
  
  <p> </p>
  
  <p>The page variable is missing there. Actually am expecting page to FALSE. Is there anyway to achive this? I mean if a value is missing, then that name should be false.</p>