title: Google Sites API: Parent link must point to the same site
body: <p>I'm attempting to create a subpage but I'm running into the error mentioned in the title. I used fiddler to get the request being sent and it looks like the following.</p>
  
  <pre><code>POST https://sites.google.com/feeds/content/domain/site/ HTTP/1.1
  Content-Type: application/atom+xml; charset=UTF-8
  User-Agent: G-google-SitesAPIDemo-v1.2/GDataGAuthRequestFactory-CS-Version=2.1.0.0
  Authorization: xxx
  GData-Version: 1.0
  Host: sites.google.com
  Content-Length: 17272
  Expect: 100-continue
  
  &lt;?xml version="1.0" encoding="utf-8"?&gt;
    &lt;entry xmlns="http://www.w3.org/2005/Atom" xmlns:gd="http://schemas.google.com/g/2005"&gt;
    &lt;sites:pageName xmlns:sites="http://schemas.google.com/sites/2008"&gt;Title&lt;/sites:pageName&gt;
    &lt;title type="text"&gt;title&lt;/title&gt;
    &lt;link href="https://sites.google.com/feeds/content/site/domain/Parent_Id" rel="http://schemas.google.com/sites/2008#parent" type="application/atom+xml" /&gt;
    &lt;category term="http://schemas.google.com/sites/2008#announcement" scheme="http://schemas.google.com/g/2005#kind" label="announcement" /&gt;
  </code></pre>
  
  <p>It matches up to the <a href="https://developers.google.com/google-apps/sites/docs/1.0/developers_guide_protocol#CreatingSubpages" rel="nofollow">api</a> for doing so but I'm not sure what seems to be the issue. </p>