Fix IDE doc for better auto-completion

lib/Elastica/Aggregation/AbstractAggregation.php

@@ -58,7 +58,7 @@ public function getAggs()
      * Add a sub-aggregation
      * @param  AbstractAggregation                  $aggregation
      * @throws \Elastica\Exception\InvalidException
-     * @return AbstractAggregation
+     * @return $this
      */
     public function addAggregation(AbstractAggregation $aggregation)
     {

lib/Elastica/Aggregation/AbstractSimpleAggregation.php

@@ -9,7 +9,7 @@ abstract class AbstractSimpleAggregation extends AbstractAggregation
     /**
      * Set the field for this aggregation
      * @param  string                    $field the name of the document field on which to perform this aggregation
-     * @return AbstractSimpleAggregation
+     * @return $this
      */
     public function setField($field)
     {
@@ -19,7 +19,7 @@ public function setField($field)
     /**
      * Set a script for this aggregation
      * @param  string|Script             $script
-     * @return AbstractSimpleAggregation
+     * @return $this
      */
     public function setScript($script)
     {

lib/Elastica/Aggregation/Histogram.php

@@ -24,7 +24,7 @@ public function __construct($name, $field, $interval)
     /**
      * Set the interval by which documents will be bucketed
      * @param  int       $interval
-     * @return Histogram
+     * @return $this
      */
     public function setInterval($interval)
     {
@@ -35,7 +35,7 @@ public function setInterval($interval)
      * Set the bucket sort order
      * @param  string    $order     "_count", "_term", or the name of a sub-aggregation or sub-aggregation response field
      * @param  string    $direction "asc" or "desc"
-     * @return Histogram
+     * @return $this
      */
     public function setOrder($order, $direction)
     {
@@ -45,7 +45,7 @@ public function setOrder($order, $direction)
     /**
      * Set the minimum number of documents which must fall into a bucket in order for the bucket to be returned
      * @param  int       $count set to 0 to include empty buckets
-     * @return Histogram
+     * @return $this
      */
     public function setMinimumDocumentCount($count)
     {

lib/Elastica/Aggregation/Range.php

@@ -15,7 +15,7 @@ class Range extends AbstractSimpleAggregation
      * @param  int|float                            $fromValue low end of this range, exclusive (greater than)
      * @param  int|float                            $toValue   high end of this range, exclusive (less than)
      * @param  string                               $key       customized key value
-     * @return Range
+     * @return $this
      * @throws \Elastica\Exception\InvalidException
      */
     public function addRange($fromValue = null, $toValue = null, $key = null)
@@ -40,7 +40,7 @@ public function addRange($fromValue = null, $toValue = null, $key = null)
     /**
      * If set to true, a unique string key will be associated with each bucket, and ranges will be returned as an associative array
      * @param  bool  $keyed
-     * @return Range
+     * @return $this
      */
     public function setKeyedResponse($keyed = true)
     {

lib/Elastica/Param.php

@@ -78,7 +78,7 @@ protected function _setRawParam($key, $value)
      *
      * @param  string          $key   Key to set
      * @param  mixed           $value Key Value
-     * @return \Elastica\Param
+     * @return $this
      */
     public function setParam($key, $value)
     {
@@ -91,7 +91,7 @@ public function setParam($key, $value)
      * Sets (overwrites) all params of this object
      *
      * @param  array           $params Parameter list
-     * @return \Elastica\Param
+     * @return $this
      */
     public function setParams(array $params)
     {
@@ -107,7 +107,7 @@ public function setParams(array $params)
      *
      * @param  string          $key   Param key
      * @param  mixed           $value Value to set
-     * @return \Elastica\Param
+     * @return $this
      */
     public function addParam($key, $value)
     {