Use the correct escape for BOM; add build code to detect non-ASCII.

grunt.js

@@ -416,6 +416,27 @@ module.exports = function( grunt ) {
			return path !== "*";
		});

		// Ensure the dist files are pure ASCII
		var fs = require("fs"),
			nonascii = false;
		distpaths.forEach(function( filename ) {
			var buf = fs.readFileSync( filename, "utf8" ),
			i, c;
			if ( buf.length !== Buffer.byteLength( buf, "utf8" ) ) {
				log.writeln( filename + ": Non-ASCII characters detected:" );
				for ( i = 0; i < buf.length; i++ ) {
					c = buf.charCodeAt( i );
					if ( c > 127 ) {
						log.writeln( "- position " + i + ": " + c );
						log.writeln( "-- " + buf.substring( i - 20, i + 20 ) );
						nonascii = true;
					}
				}
			}
		});
		if ( nonascii ) {
			return false;
		}

		// Proceed only if there are actual
		// paths to write to

src/core.js

@@ -605,7 +605,7 @@ jQuery.extend({
	},

	// Use native String.trim function wherever possible
	trim: core_trim && !core_trim.call("\xFEFF\xA0") ?
	trim: core_trim && !core_trim.call("\uFEFF\xA0") ?
		function( text ) {
			return text == null ?
				"" :