Code patch for event/browser.js

Hi,

[Apologies for spamming the list, but I'm not yet eligible for direct 
check-ins.]

I have noticed an obscure IE6 bug is triggered by the event.stopEvent() 
method.  The stopEvent method just chains together the Microsoft 
equivalent of preventDefault() and stopPropagation().

But for the event "onselectstart", which is an IE-only event which fires 
when the user begins to select text with the cursor, using stopEvent on 
this type of event throws errors from within the "run" method with 
extended onto dojo.event.MethodJoinPoint.

I have no idea why IE chooses to exhibit this problem for this type of 
event.  But the fix is simple:

On rev. 6380 of event/browser.js, at line 496:

change:
       if(window.event){
           evt.returnValue = false;
           evt.cancelBubble = true;


to:
       if(window.event){
           evt.cancelBubble = true;
           evt.returnValue = false;