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/extra_header_id.md

@@ -0,0 +1,86 @@
+Write a comment abouth the test here.
+*** Parameters: ***
+{:title=>"Header 1"}
+*** Markdown input: ***
+Header 1            {#header1}
+========
+
+Header 2            {#header2}
+--------
+
+### Header 3 ###      {#header3}
+
+Then you can create links to different parts of the same document like this:
+
+[Link back to header 1](#header1),
+[Link back to header 2](#header2),
+[Link back to header 3](#header3)
+
+*** Output of inspect ***
+md_el(:document,[
+	md_el(:header,["Header 1"],{:level=>1},[[:id, "header1"]]),
+	md_el(:header,["Header 2"],{:level=>2},[[:id, "header2"]]),
+	md_el(:header,["Header 3"],{:level=>3},[[:id, "header3"]]),
+	md_par([
+		"Then you can create links to different parts of the same document like this:"
+	]),
+	md_par([
+		md_im_link(["Link back to header 1"], "#header1", nil),
+		", ",
+		md_im_link(["Link back to header 2"], "#header2", nil),
+		", ",
+		md_im_link(["Link back to header 3"], "#header3", nil)
+	])
+],{},[])
+*** Output of to_html ***
+<h1 id='header1'>Header 1</h1>
+
+<h2 id='header2'>Header 2</h2>
+
+<h3 id='header3'>Header 3</h3>
+
+<p>Then you can create links to different parts of the same document like this:</p>
+
+<p><a href='#header1'>Link back to header 1</a>, <a href='#header2'>Link back to header 2</a>, <a href='#header3'>Link back to header 3</a></p>
+*** Output of to_latex ***
+\hypertarget{header1}{}\section*{{Header 1}}\label{header1}
+
+\hypertarget{header2}{}\subsection*{{Header 2}}\label{header2}
+
+\hypertarget{header3}{}\subsubsection*{{Header 3}}\label{header3}
+
+Then you can create links to different parts of the same document like this:
+
+\hyperlink{header1}{Link back to header 1}, \hyperlink{header2}{Link back to header 2}, \hyperlink{header3}{Link back to header 3}
+*** Output of to_md ***
+Header 1Header 2Header 3Then you can create links to different
+parts of the same document like this:
+
+Link back to header 1,
+Link back to header 2,
+Link back to header 3
+*** Output of to_s ***
+Header 1Header 2Header 3Then you can create links to different parts of the same document like this:Link back to header 1, Link back to header 2, Link back to header 3
+*** EOF ***
+
+
+
+	OK!
+
+
+
+*** Output of Markdown.pl ***
+<h1>Header 1            {#header1}</h1>
+
+<h2>Header 2            {#header2}</h2>
+
+<h3>Header 3 ###      {#header3}</h3>
+
+<p>Then you can create links to different parts of the same document like this:</p>
+
+<p><a href="#header1">Link back to header 1</a>,
+<a href="#header2">Link back to header 2</a>,
+<a href="#header3">Link back to header 3</a></p>
+
+*** Output of Markdown.pl (parsed) ***
+Error: #<NoMethodError: private method `write_children' called for <div> ... </>:REXML::Element>