Forms: try to give dev UI more hints on fluent...

...code

application/forms/IcingaHostForm.php

@@ -38,15 +38,16 @@ class IcingaHostForm extends DirectorObjectForm
              ->addAddressElements()
              ->addDisabledElement()
              ->groupMainProperties()
-             ->addClusteringElements()
-             ->addCheckCommandElements()
+             ->addClusteringElements();
+
+        $this->addCheckCommandElements()
              ->addCheckExecutionElements()
              ->addExtraInfoElements()
              ->setButtons();
     }
 
     /**
-     * @return self
+     * @return $this
      */
     protected function addClusteringElements()
     {
@@ -127,7 +128,7 @@ class IcingaHostForm extends DirectorObjectForm
     }
 
     /**
-     * @return self
+     * @return $this
      */
     protected function addGroupsElement()
     {
@@ -153,7 +154,7 @@ class IcingaHostForm extends DirectorObjectForm
     }
 
     /**
-     * @return self
+     * @return $this
      */
     protected function addAddressElements()
     {
@@ -178,7 +179,7 @@ class IcingaHostForm extends DirectorObjectForm
     }
 
     /**
-     * @return self
+     * @return $this
      */
     protected function addDisplayNameElement()
     {

library/Director/Web/Form/DirectorObjectForm.php

@@ -372,7 +372,7 @@ abstract class DirectorObjectForm extends QuickForm
     }
 
     /**
-     * @return self
+     * @return $this
      */
     protected function groupMainProperties()
     {
@@ -1035,7 +1035,7 @@ abstract class DirectorObjectForm extends QuickForm
     /**
      * @param bool $force
      *
-     * @return self
+     * @return $this
      */
     protected function addCheckCommandElements($force = false)
     {
@@ -1268,7 +1268,7 @@ abstract class DirectorObjectForm extends QuickForm
      *
      * @param array  $properties Form element properties
      *
-     * @return self
+     * @return $this
      */
     protected function addAssignFilter($properties)
     {
@@ -1301,7 +1301,7 @@ abstract class DirectorObjectForm extends QuickForm
      * @param string $name       Element name
      * @param array  $properties Form element properties
      *
-     * @return self
+     * @return $this
      */
     protected function addFilterElement($name, $properties)
     {