patch by ddk r=bbaetz r=justdave
Bug 135666 Creating bugs: OS detection doesn't work for Internet Explorer, Win NT 4.
patch by ddk+johannes.pellenz@sdm.de r=bbaetz r=justdave

Adds Windows XP to the bugzilla OS list
Activates the Windows XP detection (it was commented out waiting for this fix...)
Makes Windows NT (4) detection match the pattern everything else used