Added imbricated query support in whereIn method (fixes #782)

lib/Doctrine/Query/Abstract.php

@@ -1170,8 +1170,19 @@ abstract class Doctrine_Query_Abstract
             if ($value instanceof Doctrine_Expression) {
                 $value = $value->getSql();
                 unset($params[$k]);
+            } else if (is_object($value) && $value instanceof Doctrine_Query) { // Imbricated Query?
+                $field = $value->getDqlPart('select');
+                $field = $field[0];
+
+                $rstemp = $value->execute();
+
+                $value = array();
+
+                foreach ($rstemp as $key => $object) { // Create a table with values in imbricated query
+                    array_push($value, $object->$field);
+                }
             } else {
-                $value = '?';          
+                $value = '?';
             }
             $a[] = $value;
         }