Update the group and project logo to account for TLP

git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@543456 13f79535-47bb-0310-9956-ffa450edef68

src/documentation/skinconf.xml

@@ -102,13 +102,13 @@ be used to configure the chosen Forrest skin.
        skin: forrest-site renders it at the top -->
   <project-name>POI</project-name>
   <project-url>http://poi.apache.org/</project-url>
-  <project-logo>resources/images/project-logo.gif</project-logo>
+  <project-logo>resources/images/project-logo.jpg</project-logo>
 
   <!-- optional group logo
        skin: forrest-site renders it at the top-left corner -->
   <group-name>Apache POI</group-name>
   <group-url>http://poi.apache.org</group-url>
-  <group-logo>resources/images/group-logo.gif</group-logo>
+  <group-logo>resources/images/group-logo.jpg</group-logo>
 
   <!-- optional host logo (e.g. sourceforge logo)
        skin: forrest-site renders it at the bottom-left corner -->