Revert "Fix #12350. Remove BOM in jQuery.trim. Close gh-897."

This reverts commit 2b5b4eb.

String.prototype.trim doesn't trim BOM in Safari 5.0 so this won't work without additional feature detects.

http://swarm.jquery.org/result/165379

AUTHORS.txt

@@ -130,5 +130,4 @@ Uri Gilad <antishok@gmail.com>
 Chris Faulkner <thefaulkner@gmail.com>
 Elijah Manor <elijah.manor@gmail.com>
 Daniel Chatfield <chatfielddaniel@googlemail.com>
-Nikita Govorov <nikita.govorov@gmail.com>
-Wesley Walser <wwalser@atlassian.com>
+Nikita Govorov <nikita.govorov@gmail.com>

src/core.js

@@ -37,8 +37,8 @@ var
 	core_rnotwhite = /\S/,
 	core_rspace = /\s+/,
 
-	// IE doesn't match many whitespace characters with \s
-	rtrim = core_rnotwhite.test("\xA0") ? /^[\s\xA0\uFEFF]+|[\s\xA0\uFEFF]+$/g : /^\s+|\s+$/g,
+	// IE doesn't match non-breaking spaces with \s
+	rtrim = core_rnotwhite.test("\xA0") ? (/^[\s\xA0]+|[\s\xA0]+$/g) : /^\s+|\s+$/g,
 
 	// A simple way to check for HTML strings
 	// Prioritize #id over <tag> to avoid XSS via location.hash (#9521)

test/unit/core.js

@@ -264,7 +264,7 @@ test("noConflict", function() {
 });
 
 test("trim", function() {
-	expect(13);
+	expect(9);
 
 	var nbsp = String.fromCharCode(160);
 
@@ -278,11 +278,6 @@ test("trim", function() {
 	equal( jQuery.trim( null ), "", "Null" );
 	equal( jQuery.trim( 5 ), "5", "Number" );
 	equal( jQuery.trim( false ), "false", "Boolean" );
-
-	equal( jQuery.trim(" "), "", "space should be trimmed" );
-	equal( jQuery.trim("ipad\xA0"), "ipad", "nbsp should be trimmed" );
-	equal( jQuery.trim("\uFEFF"), "", "zwsp should be trimmed" );
-	equal( jQuery.trim("\uFEFF \xA0! | \uFEFF"), "! |", "leading/trailing should be trimmed" );
 });
 
 test("type", function() {