Instead of having the whole migration script added, you could simply add the following (extracted from the migration script)
$.uaMatch = function( ua ) {
ua = ua.toLowerCase();
var match = /(chrome)[ \/]([\w.]+)/.exec( ua ) ||
/(webkit)[ \/]([\w.]+)/.exec( ua ) ||
/(opera)(?:.*version|)[ \/]([\w.]+)/.exec( ua ) ||
/(msie) ([\w.]+)/.exec( ua ) ||
ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([\w.]+)|)/.exec( ua ) ||
[];
return {
browser: match[ 1 ] || "",
version: match[ 2 ] || "0"
};
};
and then use it like so
$.uaMatch(navigator.userAgent)