Update doxygen doc to reflet vbo changes.

Update doxygen doc, array_cache no longuer exist,
new shiny vbo modules is there. Tested on unix,
but i think i didn't broke that bat :).
diff --git a/doxygen/tnl_dd.doxy b/doxygen/tnl_dd.doxy
index b7bd6e9..b241f67 100644
--- a/doxygen/tnl_dd.doxy
+++ b/doxygen/tnl_dd.doxy
@@ -45,5 +45,5 @@
                          swrast.tag=../swrast \
                          swrast_setup.tag=../swrast_setup \
                          tnl.tag=../tnl \
-                         array_cache.tag=array_cache
+                         vbo.tag=vbo
 GENERATE_TAGFILE       = tnl_dd.tag