issue #12 xml消息fromXml, toXml有错误

src/test/java/chanjarster/weixin/bean/WxXmlOutImageMessageTest.java

@@ -0,0 +1,28 @@
+package chanjarster.weixin.bean;
+
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+@Test
+public class WxXmlOutImageMessageTest {
+
+  public void test() {
+    WxXmlOutImageMessage m = new WxXmlOutImageMessage();
+    m.setMediaId("ddfefesfsdfef");
+    m.setCreateTime(1122l);
+    m.setFromUserName("from");
+    m.setToUserName("to");
+    
+    String expected = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>" 
+        + "<xml>"
+        + "<ToUserName><![CDATA[to]]></ToUserName>"
+        + "<FromUserName><![CDATA[from]]></FromUserName>"
+        + "<CreateTime>1122</CreateTime>"
+        + "<MsgType><![CDATA[image]]></MsgType>"
+        + "<Image><MediaId><![CDATA[ddfefesfsdfef]]></MediaId></Image>"
+        + "</xml>";
+    System.out.println(m.toXml());
+    Assert.assertEquals(m.toXml().replaceAll("\\s", ""), expected.replaceAll("\\s", ""));
+  }
+  
+}