Correct NameID api docs and add an example.

docs/simplesamlphp-sp-api.md

@@ -226,7 +226,8 @@ See the [`saml:SP`](./saml:sp) reference for information about available SAML au
 ### Example
 
     $idp = $auth->getAuthData('saml:sp:IdP');
-    print('You are logged in from: ' . htmlspecialchars($idp));
+    $nameID = $auth->getAuthData('saml:sp:NameID')->getValue();
+    printf('You are %s, logged in from %s', htmlspecialchars($nameID), htmlspecialchars($idp));
 
 
 `getLoginURL`

modules/saml/docs/sp.md

@@ -94,7 +94,7 @@ The following attributes are available:
 
 `saml:sp:NameID`
 :   The NameID the user was issued by the IdP.
-    This is an associative array with the various fields from the NameID.
+    This is a \SAML2\XML\saml\NameID object with the various fields from the NameID.
 
 `saml:sp:SessionIndex`
 :   The SessionIndex we received from the IdP.