MyBatis format XNode toString method.

Format class XNode toString method, make the sub label retract a 'tab'. eclipse "ctrl+shift+i" to watch the value of variable friendly.

Comment From: Dreamroute

@harawata I have add a test case.pls check.

Comment From: harawata

Thanks for the update, @Dreamroute !

There seems to be a problem with a node with 3+ levels. Try this test:

@Test
public void formatXNodeToStringDeep() {
  XPathParser parser = new XPathParser("<a><b><c><d>text</d></c></b></a>");
  String actual = parser.evalNode("/a").toString();
  String expect = "<a>\n\t<b>\n\t\t<c>\n\t\t\t<d>text</d>\n\t\t</c>\n\t</b>\n</a>\n";
  assertEquals(expect, actual);
}

Comment From: Dreamroute

@harawata I have solve the 3+ level format and add 3 test case.

Comment From: Dreamroute

@harawata your 2 suggest have done.

Comment From: harawata

Hi @Dreamroute . It's merged. I cleaned up your commits and force-pushed. Hope you don't mind. Thanks again for your work!

Comment From: harawata

HI @Dreamroute ,

I noticed that this patch is not good enough for actual mapper statements. Here is an example (a node contains both body text and a child element):

<select id="getUser" resultType="org.apache.ibatis.submitted.foreach.User">
  select * from users WHERE id in (
  <foreach item="friendList" index="index" collection="friendList" separator=",">
    #{friendList.id}
  </foreach>
  )
</select>

Do you think you can fix it?