title: ElasticSearch Update failing because of tag name?
body: <p>For my given ElasticSearch document, I can update the value of a particular field named "ResourcePort".  But the update fails with "Illegal Argument Exception" when I try and update the field name "Domain.threat".  Is it because the field name has a "dot" in it?  My code running in the sense plugin is </p>
  
  <pre><code> POST /foo/bar/12/_update
   {"script":"ctx._source.Domain.threat='bad'"}
  </code></pre>
  
  <p>But this works</p>
  
  <pre><code> POST /foo/bar/12/_update
   {"script":"ctx._source.ResourcePort='bad'"}
  </code></pre>
  
  <p>EDITED:
  My ES version is 1.1.0
  The Domain.threat field is "Domain.threat":{"type":"string"}</p>