docs: use UTF-8 instead of HTML entities for decorated letters

We have files which use HTML entities for decorating letters
with unlauts, accents, etc. Other files just use UTF-8
characters directly for this. Remove the HTML entities since
they have no benefit and use UTF-8 instead.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

docs/apps.html.in

@@ -353,7 +353,7 @@
       </dd>
       <dt><a href="http://honk.sigxcpu.org/projects/libvirt/#munin">Munin</a></dt>
       <dd>
-        The plugins provided by Guido G&uuml;nther allow to monitor various things
+        The plugins provided by Guido Günther allow to monitor various things
         like network and block I/O with
         <a href="http://munin.projects.linpro.no/">Munin</a>.
       </dd>

docs/csharp.html.in

@@ -115,7 +115,7 @@ git clone git://libvirt.org/libvirt-csharp.git
     <p>
       The C# bindings are the work of Arnaud Champion
       &lt;<a href="mailto:arnaud.champion AT devatom.fr">arnaud.champion AT devatom.fr</a>&gt;,
-      based upon the previous work of Jarom&iacute;r &#x010C;ervenka.
+      based upon the previous work of Jaromír Červenka.
     </p>
 
     <h2><a id="notes">Test Configuration</a></h2>