title: Remove search operator (AND/OR) in multiplesearch jqGrid
body: <p>I need to hide the operator in the search popup, but I cannot get it to work. 
  I tried this, but both operators still appear:</p>
  
  <pre><code>
  jQuery("#grilla").navGrid("#paginador",
  {del:false,add:false,edit:false},{},{},{},{
  groupOps: [{ op: "OR", text: "any" }], multipleSearch:true});
  </code></pre>
  
  <p>Any ideas?
  Thanks!</p>