e>EventDirContext</code>,
through which applications can register their interest in events
fired by the context.
<p>
<code>NamingEvent</code> represents an event that occurs in a 
naming or directory service. There are two categories of naming events:
<ul>
<li>Those that affect the namespace (add/remove/rename an object)
<li>Those that affect the objects' contents.
</ul>
Each category of events is handled by a corresponding listener:
<code>NamespaceChangeListener</code>, <code>ObjectChangeListener</code>.
<