Add Google Analytics javascript to Mocha docs.

Customising YARD templates is a bit obscure and this was the best I
could come up with. The javascript appears as the last section within
the content div, but before the footer div. Not ideal, but I think it
should be ok.

The tracking javascript is only displayed if the
`GOOGLE_ANALYTICS_WEB_PROPERTY_ID` environment variable is set.

.yardopts

@@ -1,3 +1,4 @@
+--template-path yard-templates
 --no-private
 lib/mocha/api.rb
 lib/mocha/hooks.rb

Rakefile

@@ -113,8 +113,14 @@ unless ENV["MOCHA_NO_DOCS"]
     `rm -rf ./doc`
   end
 
+  task 'docs_environment' do
+    unless ENV['GOOGLE_ANALYTICS_WEB_PROPERTY_ID']
+      puts "\nWarning: GOOGLE_ANALYTICS_WEB_PROPERTY_ID was not defined\n\n"
+    end
+  end
+
   desc 'Generate documentation'
-  YARD::Rake::YardocTask.new('yardoc') do |task|
+  YARD::Rake::YardocTask.new('yardoc' => 'docs_environment') do |task|
     task.options = ["--title", "Mocha #{Mocha::VERSION}"]
   end
 

yard-templates/default/layout/html/google_analytics.erb

@@ -0,0 +1,11 @@
+<script src="/javascripts/app.js" type="text/javascript" charset="utf-8"></script>
+
+<script type="text/javascript">
+var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
+document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
+</script>
+<script type="text/javascript">
+try {
+var pageTracker = _gat._getTracker("<%= ENV['GOOGLE_ANALYTICS_WEB_PROPERTY_ID'] %>");
+pageTracker._trackPageview();
+} catch(err) {}</script>

yard-templates/default/layout/html/setup.rb

@@ -0,0 +1,6 @@
+def init
+  super
+  if ENV['GOOGLE_ANALYTICS_WEB_PROPERTY_ID']
+    sections[:layout] << :google_analytics
+  end
+end