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/syntax_hl.md

@@ -0,0 +1,80 @@
+Write a comment abouth the test here.
+*** Parameters: ***
+{}
+*** Markdown input: ***
+This is ruby code:
+
+	require 'maruku'
+	
+	puts Maruku.new($stdin).to_html
+
+This is ruby code:
+
+	require 'maruku'
+{: lang=ruby html_use_syntax}
+	
+	puts Maruku.new($stdin).to_html
+*** Output of inspect ***
+md_el(:document,[
+	md_par(["This is ruby code:"]),
+	md_el(:code,[],{:raw_code=>"require 'maruku'\n\nputs Maruku.new($stdin).to_html"},[]),
+	md_par(["This is ruby code:"]),
+	md_el(:code,[],{:raw_code=>"require 'maruku'"},[["lang", "ruby"], [:ref, "html_use_syntax"]]),
+	md_el(:code,[],{:raw_code=>"puts Maruku.new($stdin).to_html"},[])
+],{},[])
+*** Output of to_html ***
+<p>This is ruby code:</p>
+
+<pre><code>require &#39;maruku&#39;
+
+puts Maruku.new($stdin).to_html</code></pre>
+
+<p>This is ruby code:</p>
+
+<pre><code class='ruby' lang='ruby'><span class='ident'>require</span> <span class='punct'>&#39;</span><span class='string'>maruku</span><span class='punct'>&#39;</span></code></pre>
+
+<pre><code>puts Maruku.new($stdin).to_html</code></pre>
+*** Output of to_latex ***
+This is ruby code:
+
+\begin{verbatim}require 'maruku'
+
+puts Maruku.new($stdin).to_html\end{verbatim}
+This is ruby code:
+
+\begin{verbatim}require 'maruku'\end{verbatim}
+\begin{verbatim}puts Maruku.new($stdin).to_html\end{verbatim}
+*** Output of to_md ***
+This is ruby code:
+
+This is ruby code:
+*** Output of to_s ***
+This is ruby code:This is ruby code:
+*** EOF ***
+
+
+
+	OK!
+
+
+
+*** Output of Markdown.pl ***
+<p>This is ruby code:</p>
+
+<pre><code>require 'maruku'
+
+puts Maruku.new($stdin).to_html
+</code></pre>
+
+<p>This is ruby code:</p>
+
+<pre><code>require 'maruku'
+</code></pre>
+
+<p>{: lang=ruby html<em>use</em>syntax}</p>
+
+<pre><code>puts Maruku.new($stdin).to_html
+</code></pre>
+
+*** Output of Markdown.pl (parsed) ***
+Error: #<NoMethodError: private method `write_children' called for <div> ... </>:REXML::Element>