Add Nova to the list of known themes

Signed-off-by: Eric Poirier <eric.poirier@eclipse-foundation.org>
diff --git a/system/app.class.php b/system/app.class.php
index 759ad0d..afb8bdb 100644
--- a/system/app.class.php
+++ b/system/app.class.php
@@ -1022,10 +1022,13 @@
       'eclipse_ide',
       'polarsys',
       'quicksilver',
-      'jakarta'
+      'jakarta',
+      'nova'
     );
 
-    if ($_theme === 'solstice') {
+    $_theme = strtolower($_theme);
+
+    if ($_theme === 'solstice' || $_theme === 'nova') {
       $_theme = 'eclipse_ide';
     }