Bad use of selector ancestor::

Hello friend,

I encountered some issues with the translation of the docbook file to the xml used by xml2rfc:

1.  When a blockquote is in a list, it considers that, because of the list, the inner &lt;t&gt; should not be added (while they have to, otherwise it is invalid) and a wrapping &lt;t&gt; is added because &lt;blockquote&gt; automatically add them without checking the context.

2.  I also got troubles because it seems that my version of pandoc add some external resources in the docbook output that can't be downloaded because of the ```--nonet```.

```
pandoc 1.12.3.1
Compiled with texmath 0.6.6, highlighting-kate 0.5.6.
Syntax highlighting is supported for the following languages:
    actionscript, ada, apache, asn1, asp, awk, bash, bibtex, boo, c, changelog,
    clojure, cmake, coffee, coldfusion, commonlisp, cpp, cs, css, curry, d,
    diff, djangotemplate, doxygen, doxygenlua, dtd, eiffel, email, erlang,
    fortran, fsharp, gnuassembler, go, haskell, haxe, html, ini, java, javadoc,
    javascript, json, jsp, julia, latex, lex, literatecurry, literatehaskell,
    lua, makefile, mandoc, markdown, matlab, maxima, metafont, mips, modelines,
    modula2, modula3, monobasic, nasm, noweb, objectivec, objectivecpp, ocaml,
    octave, pascal, perl, php, pike, postscript, prolog, python, r,
    relaxngcompact, restructuredtext, rhtml, roff, ruby, rust, scala, scheme,
    sci, sed, sgml, sql, sqlmysql, sqlpostgresql, tcl, texinfo, verilog, vhdl,
    xml, xorg, xslt, xul, yacc, yaml
Default user data directory: /home/openerp/.pandoc
Copyright (C) 2006-2013 John MacFarlane
Web:  http://johnmacfarlane.net/pandoc
This is free software; see the source for copying conditions.  There is no
warranty, not even for merchantability or fitness for a particular purpose.
```

Also, I've made the test with and without my fixes, the draft.txt in results does not differs.

Thanks for you work, it's great! :)

Cheers