docs: Update to generate proper google analytics code

This commit also includes minor doxygen style improvement.

Change-Id: I5ced859c0759a2fd0240068296949067f9ac4c46
diff --git a/wscript b/wscript
index e985314..080c8c0 100644
--- a/wscript
+++ b/wscript
@@ -30,6 +30,7 @@
 GIT_TAG_PREFIX = "NFD-"
 
 from waflib import Logs, Utils, Context
+import os
 
 def options(opt):
     opt.load(['compiler_cxx', 'gnu_dirs'])
@@ -228,9 +229,15 @@
     else:
         bld(features="subst",
             name="doxygen-conf",
-            source="docs/doxygen.conf.in",
-            target="docs/doxygen.conf",
+            source=["docs/doxygen.conf.in",
+                    "docs/named_data_theme/named_data_footer-with-analytics.html.in"],
+            target=["docs/doxygen.conf",
+                    "docs/named_data_theme/named_data_footer-with-analytics.html"],
             VERSION=VERSION_BASE,
+            HTML_FOOTER="../build/docs/named_data_theme/named_data_footer-with-analytics.html" \
+                          if os.getenv('GOOGLE_ANALYTICS', None) \
+                          else "../docs/named_data_theme/named_data_footer.html",
+            GOOGLE_ANALYTICS=os.getenv('GOOGLE_ANALYTICS', ""),
             )
 
         bld(features="doxygen",