[#4766] - Unable able to drag reports to dashboard with IE11

It's not possible to drag & drop reports on to a Dashboard using IE11.
The cause is changes to supported JavaScript methods in IE11.

Resolution is to check for IE11 and use the new method.
Filename: dashboard.designer.js
Row: 280

if(isIE11()){
//$(object).onselectstart = function(){return false;}
$(object).addEventListener('onselectstart', function (e) {
var tagName = e.srcElement.tagName;
if (tagName != "INPUT" && tagName != "TEXTAREA") { e.returnValue = false; }
});
} else if(isIE()){
//$(object).onselectstart = function(){return false;}
$(object).attachEvent('onselectstart', function (e) {
var tagName = e.srcElement.tagName;
if (tagName != "INPUT" && tagName != "TEXTAREA") { e.returnValue = false; }
});