find-grep makes raw terminal ANSI

[jidanni]

Why when I append additional filters on find-grep, are the results
flaky? Ah, one day instead of those filters, I tried cat -v:

(find-grep "find . -type f -print0 | xargs -0 -e grep -nH -e table|cat -v")
./article-category.html:298: </^[[01;31mtable^[[m>

That's right: raw terminal highlighting characters right there in the
output. Gentlemen, I'm sure this is the wrong layer to do this. Or at
least warn in the docstring to find-grep. emacs-version "22.1.1"