A fix for IE8

[mgussekloo]

Just something I discovered: Making sure the formatterredactor::run() method uses case-insensitive preg_replace enables Redactor in IE8. Formatter.redactor.php, line 17:

$string = preg_replace('/<(img|hr|br|link|meta|input|param|base|area|meta)((\s+\w+(\s*=\s*("[^"]*"|\'[^\']*\'|\w+))?)*)\s*>/i', '<$1$2/>', $string);