title: Get value from the people picker and add it to a list in a person column
body: <p>I have a simple JS form on my SP16 site where I added this standard people picker:</p>
  
  <pre><code>$(document).ready(function() {  
  initializePeoplePicker('pickerUAT');
  function initializePeoplePicker(peoplePickerElementId) {
  var schema = {};
  schema['PrincipalAccountType'] = 'User,DL,SecGroup,SPGroup';
  schema['SearchPrincipalSource'] = 15;
  schema['ResolvePrincipalSource'] = 15;
  schema['AllowMultipleValues'] = false;
  schema['MaximumEntitySuggestions'] = 50;
  schema['Width'] = '269px';
  this.SPClientPeoplePicker_InitStandaloneControlWrapper(peoplePickerElementId, null, schema);
  }
  });
  </code></pre>
  
  <p>I am able to get the selected value (as a display name, email, whatever) from the picker like this:</p>
  
  <pre><code>function getEmailFromPeoplePicker(title) {
  var ppDiv = $("div[title='" + title + "']")[0];
  var peoplePicker = SPClientPeoplePicker.SPClientPeoplePickerDict.pickerUAT_TopSpan;
  var userList = peoplePicker.GetAllUserInfo();
  var userInfo = userList[0];
  var addThisUser;
  if(userInfo != null)
  {
  addThisUser = userInfo.Key;
  }
  return addThisUser;
  }
  </code></pre>
  
  <p>And I have a list to which I can add other values taken from other form fields, usually through document.getElementById("XXX").value and this piece of code:</p>
  
  <pre><code>function addSubUser(addThisValue)  {
  var clientContext = new SP.ClientContext(siteurl);  
  var itemCreateInfo = new SP.ListItemCreationInformation();  
  var valueToAdd = addThisValue; 
  var list = clientContext.get_web()  
  .get_lists()  
  .getByTitle("UAT");   
  this.oListItem = list.addItem(itemCreateInfo);  
  oListItem.set_item('userUAT', valueToAdd);  
  oListItem.update();  
  clientContext.load(oListItem);  
  clientContext.executeQueryAsync(Function.createDelegate(this, this.onQuerySucceeded), Function.createDelegate(this, this.onQueryFailed));  
  }
  </code></pre>
  
  <p>However, this code doesn't work for the value taken from the people picker. Console.log(typeof addThisUser) tells me the value I get from the picker is just a string, do I assume correctly that I cannot simply add a string to a person/group column? In any event, how can I make it work?</p>