title: configurable sitemesh pattern in decorator.xml
body: <p>Is it possible to add some configurable parameter in decorator.xml?
  I need to do something like:</p>
  
  <pre><code>&lt;decorator name="sample" page="sample.jsp"&gt;
        &lt;pattern&gt;/sample.${my.own.ext}&lt;/pattern&gt;
  &lt;/decorator&gt;
  
  &lt;decorator name="example" page="example.jsp"&gt;
        &lt;pattern&gt;/example.${my.own.ext}&lt;/pattern&gt;          
  &lt;/decorator&gt; 
  </code></pre>
  
  <p>and in some config file mycfg.parameters put:</p>
  
  <p>my.own.ext=myhtm</p>
  
  <p>so it can be changed for other service</p>
  
  <p>are there any solutions for this other then creating many decorator.xml files for other services?</p>