Update to latest HTML5lib, Add Maruku testdir

Sync with the latest html5lib.
Having the Maruku unit tests on-hand may be useful for debugging; so let's include them.

vendor/plugins/maruku/tests/s5/s5profiling.md

@@ -0,0 +1,48 @@
+subtitle: news
+author: Andrea Censi
+company: Università La Sapienza
+css: math.css
+
+RDK news
+========
+
+Profiling
+---------------------------------------------------------
+
+1. `ragent2` writes profiling information on a pipe.
+2. `rdk-profiler` reads the pipe and creates graphs in HTML+Javascript.
+3. The user reads the data on a browser. 
+
+Things logged
+-----------------------------------------------------------
+
+	17288397 1730000 0 16384 END pantiltClient 
+	17288439 1730000 0 16384 START pantiltClient 
+	17288564 1730000 0 16384 LOCK pantiltClient:tilt 
+	17288622 1730000 0 16384 UNLOCK pantiltClient:tilt
+
+* `START/END`: how much does it take to ...?
+
+Footnotes 1/2
+---------------------------------------------------
+
+You can use footnotes [^1]
+
+[^1]: And they work.
+
+Footnotes 2/2
+---------------------------------------------------
+
+Each footnote on its page [^2]
+
+[^2]: alone.
+
+And now: math!
+---------------------------------------------------
+
+Consider, for example the group $\int_{a}^{b} x^{a} db$ of 
+
+\[         \alpha_{\beta}^{\gamma} \]
+
+Unfortunately S5 and MathML are mutually exclusive. 
+See <http://meyerweb.com/eric/thoughts/category/tech/s5/> for explanations.