add more calbacks; documentation changes

documentation/htmldoxygen/pvaClientMonitorRequester.html

@@ -35,10 +35,31 @@
 
 <h1>PvaClientMonitorRequester</h1>
 
+<p>This is a virtual class that can be implemented by a client that uses <b>PvaClientMonitor</b>.
+It has the methods:</p>
+<pre>
+virtual void monitorConnect(
+    const Status&amp; status,
+    PvaClientMonitorPtr const &amp; clientMonitor,
+    StructureConstPtr const &amp; structure) {}
+virtual void event(
+    PvaClientMonitor const &amp; clientGet) = 0;
+virtual void unlisten()
+{
+     std::cerr &lt;&lt; "PvaClientMonitorRequester::unlisten called"
+               &lt;&lt; " but no PvaClientMonitorRequester::unlisten\n";
+}
+</pre>
+
+<p>The client must call</p>
+<pre>
+pvaClientMonitor->setRequester(shared_from_this());
+</pre>
 <p>
-<b>Not Yet Written</b>
+after creating an instance of PvaClientMonitor.
 </p>
 
+
 </body>
 </html>