[*] Theme : Improved <HTML> language

<html lang="en"> to <html lang="{$lang_iso}" from :
<!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7 lt-ie6 "
lang="en"> <![endif]-->
<!--[if IE 7]>    <html class="no-js ie7 lt-ie9 lt-ie8" lang="en">
<![endif]-->
<!--[if IE 8]>    <html class="no-js lt-ie9 ie8" lang="en"> <![endif]-->
<!--[if gt IE 8]> <html lang="fr" class="no-js ie9" lang="en">
<![endif]-->
and remove lang="fr" from:
<!--[if gt IE 8]> <html lang="fr" class="no-js ie9" lang="en">
<![endif]-->