added html image map to Handle Hierarchy image

Scheduler/Scheduler.hh

@@ -179,13 +179,14 @@ namespace senf {
             sole member is a typedef symbol defining the callback type given the handle type.
 
             The Callback is any callable object taking a \c Handle and an \c EventId as argument.
-        template <class Handle>
-        struct GenericCallback {
-            typedef boost::function<void (typename boost::call_traits<Handle>::param_type,
-                                          EventId) > Callback;
-        };
+            \code
+            template <class Handle>
+            struct GenericCallback {
+                typedef boost::function<void (typename boost::call_traits<Handle>::param_type,
+                                              EventId) > Callback;
+            };
+            \endcode
          */
-
         typedef boost::function<void (EventId)> FdCallback;
 
         /** \brief Callback type for timer events */

Socket/FileHandle.hh

@@ -26,7 +26,19 @@
 
 /** \defgroup handle_group The Handle Hierarchy
 
-    \image html FhHierarchy.png
+    \htmlonly 
+    <map name="FhHierarchy">
+      <area shape="rect" alt="FileHandle" href="classsenf_1_1FileHandle.html" title="FileHandle" coords="247,1,345,27" />
+      <area shape="rect" alt="SocketHandle" href="classsenf_1_1SocketHandle.html" title="SocketHandle" coords="235,61,355,87" />
+      <area shape="rect" alt="ClientSocketHandle" href="classsenf_1_1ClientSocketHandle.html" title="ClientSocketHandle" coords="32,140,198,167" />
+      <area shape="rect" alt="ServerSocketHandle" href="classsenf_1_1ServerSocketHandle.html" title="ServerSocketHandle" coords="386,140,558,168" />
+      <area shape="rect" alt="ProtocolServerSocketHandle" href="classsenf_1_1ProtocolServerSocketHandle.html" title="ProtocolServerSocketHandle" coords="354,202,590,228" />
+      <area shape="rect" alt="ProtocolClientSocketHandle" href="classsenf_1_1ProtocolClientSocketHandle.html" title="ProtocolClientSocketHandle" coords="1,202,230,228" />
+    </map>
+    <center>
+      <img src="FhHierarchy.png" border="0" alt="FhHierarchy" usemap="#FhHierarchy">
+    </center>
+    \endhtmlonly
 
     The senf::FileHandle class is the base of a hierarchy of socket handle classes (realized as
     templates). These classes provide an interface to the complete socket API. While going down the