[jQuery] isXMLDoc identical with Sizzle's isXML

[Manuel Strehl]

Hi,

just wanted to mention, that jQuery.extend.isXMLDoc (jQuery 1.3.2 line
#640) is essentially identical with Sizzle's isXML (jQuery 1.3.2 line
#2338). Perhaps they should be joined in a way, that is, jQuery should
use Sizzle's?

Cheers,
Manuel