Support to multibyte in subject.

Author: jrbasso

lib/Cake/Network/CakeEmail.php

@@ -475,7 +475,7 @@ public function subject($subject = null) {
 		if ($subject === null) {
 			return $this->_subject;
 		}
-		$this->_subject = (string)$subject;
+		$this->_subject = $this->_encode((string)$subject);
 		return $this;
 	}
 

lib/Cake/tests/Case/Network/CakeEmailTest.php

@@ -342,6 +342,10 @@ public function testSubject() {
 		$result = $this->CakeEmail->subject(array('something'));
 		$this->assertIdentical($this->CakeEmail->subject(), 'Array');
 		$this->assertIdentical($this->CakeEmail, $result);
+
+		$this->CakeEmail->subject('هذه رسالة بعنوان طويل مرسل للمستلم');
+		$expected = '=?UTF-8?B?2YfYsNmHINix2LPYp9mE2Kkg2KjYudmG2YjYp9mGINi32YjZitmEINmF2LE=?=' . "\r\n" . ' =?UTF-8?B?2LPZhCDZhNmE2YXYs9iq2YTZhQ==?=';
+		$this->assertIdentical($this->CakeEmail->subject(), $expected);
 	}
 
 /**