Merge the Doxygen configuration files from the embedded branch.
diff --git a/doxygen/header_subset.html b/doxygen/header_subset.html
new file mode 100644
index 0000000..1579e5d
--- /dev/null
+++ b/doxygen/header_subset.html
@@ -0,0 +1,9 @@
+<html><head><title>Mesa Source Code Documentation</title>
+<link href="doxygen.css" rel="stylesheet" type="text/css">
+</head>
+<body><center>
+<a href="../core_subset/index.html">Mesa Core</a>
+<a href="../math_subset/index.html">math</a>
+<a href="../miniglx/index.html">MiniGLX</a>
+<a href="../radeon_subset/index.html">radeon_subset</a>
+</center>