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/unittest/lists7.md

@@ -0,0 +1,79 @@
+I'm not sure if this should work at all...
+
+*** Parameters: ***
+{} # params 
+*** Markdown input: ***
+Ciao
+
+*	Tab
+	*	Tab
+		*	Tab
+
+*** Output of inspect ***
+nil
+*** Output of to_html ***
+<p>Ciao</p>
+
+<ul>
+<li>Tab * Tab * Tab</li>
+</ul>
+*** Output of to_latex ***
+Ciao
+
+\begin{itemize}%
+\item Tab * Tab * Tab
+
+\end{itemize}
+*** Output of to_md ***
+Ciao
+
+-ab * Tab * Tab
+*** Output of to_s ***
+CiaoTab * Tab * Tab
+*** EOF ***
+
+
+
+
+Failed tests:   [:inspect] 
+
+*** Output of inspect ***
+-----| WARNING | -----
+md_el(:document,[
+	md_par(["Ciao"]),
+	md_el(:ul,[md_el(:li_span,["Tab * Tab * Tab"],{:want_my_paragraph=>false},[])],{},[])
+],{},[])
+*** Output of to_html ***
+<p>Ciao</p>
+
+<ul>
+<li>Tab * Tab * Tab</li>
+</ul>
+*** Output of to_latex ***
+Ciao
+
+\begin{itemize}%
+\item Tab * Tab * Tab
+
+\end{itemize}
+*** Output of to_md ***
+Ciao
+
+-ab * Tab * Tab
+*** Output of to_s ***
+CiaoTab * Tab * Tab
+*** Output of Markdown.pl ***
+<p>Ciao</p>
+
+<ul>
+<li>Tab
+<ul>
+<li>Tab
+<ul>
+<li>Tab</li>
+</ul></li>
+</ul></li>
+</ul>
+
+*** Output of Markdown.pl (parsed) ***
+Error: #<NoMethodError: private method `write_children' called for <div> ... </>:REXML::Element>