Update website to point to 5.0.100 release.

index.php

diff --git a/index.php b/index.php
index 390af4b..49c8c6d 100644
--- a/index.php
+++ b/index.php
@@ -50,8 +50,8 @@
 
 <div id="headlines">
 
-<h3>Release 5.0.0 Available</h3>
-<p><i>Juni 28, 2017 -</i> Release <a href="https://projects.eclipse.org/projects/tools.gef/releases/5.0.0-oxygen">5.0.0</a> is available as part of the Oxygen simultaneous release, including major revisions of all GEF components. Follow the <a href="/gef/downloads/index.php">Download</a> link to obtain it. 
+<h3>Release 5.0.100 Available</h3>
+<p><i>Juni 27, 2018 -</i> Release <a href="https://projects.eclipse.org/projects/tools.gef/releases/5.0.100-photon">5.0.100</a> is available as part of the Photon simultaneous release, including service revisions of all GEF components. Follow the <a href="/gef/downloads/index.php">Download</a> link to obtain it. 
 </p>
 
 </div>