code: private boolean isSipServletDirectory(File dir) {
  		 if(dir.isDirectory()) {
  			 //Fix provided by Thomas Leseney for exploded directory deployments
  			File sipXmlFile = new File(dir.getAbsoluteFile(), SipContext.APPLICATION_SIP_XML);
  			if(sipXmlFile.exists()) {
  				return true;
  			}
  			if(SipApplicationAnnotationUtils.findPackageInfoinDirectory(dir)) return true;
  		}		
  		return false;
  	}
docs: Check if the file given in parameter match a sip servlet application, i.e.
  if it contains a sip.xml in its WEB-INF directory
  @param file the file to check (war or sar)
  @return true if the file is a sip servlet application, false otherwise