Completely removed the html5lib sanitizer.
Fixed the string-handling to work in both
Ruby 1.8.x and 1.9.2. There are still,
inexplicably, two functional tests that
fail. But the rest seems to work quite well.
Some more tests from Clint Ruoho. The main branch of Instiki (and, I guess,
the old sanitizer) are vulnerable.
Also: under Ruby 1.8.x, CGI.unescapeHTML screws up horribly decoding NCRs
which represent high-bit ASCII characters. UTF-8 agrees with 7-bit ASCII,
but CGI.unescapeHTML doesn't seem to know that they disagree for i>127.
Fixed a bug in the HTML5lib tokenizer (affects S5 slideshows).
Some miscellaneous code cleanup. In particular, don't bother with zapping control characters;
instead, rely on is_utf8? method to raise an exception (which we do anyway).