add a custom field long choice basic

The `custom field long choice` aim to provide a way to deal with choices
with a big possibilities.

The `custom field long choice` allow :
- to persist different options in the database ;
- each option has a key, a text (translatable string), and eventually a
  parent, and an internal_key
- every key can be activate or not. If the parent is inactivated, all
  childs are inactivated
- the internal key have two purposes :
    - link to an external csv file, with their own key ;
    - add a special class to results, to allow custom layout.

Currently, the field exists, but some elements are missing :

- a script for CSV import
- possibility to select multiple items
- edition of options
- handle of option without parents
- tests are missing

EntityRepository/CustomFieldLongChoice/OptionRepository.php

@@ -0,0 +1,77 @@
+<?php
+
+/*
+ * Copyright (C) 2015 Julien Fastré <julien.fastre@champs-libres.coop>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace Chill\CustomFieldsBundle\EntityRepository\CustomFieldLongChoice;
+
+use Doctrine\ORM\EntityRepository;
+use Chill\CustomFieldsBundle\Entity\CustomFieldLongChoice\Option;
+
+/**
+ * 
+ *
+ * @author Julien Fastré <julien.fastre@champs-libres.coop>
+ */
+class OptionRepository extends EntityRepository
+{
+    /**
+     * 
+     * @param string $key
+     * @return Option[]
+     */
+    public function findFilteredByKey($key, $includeParents = true, $active = true)
+    {
+        $qb = $this->createQueryBuilder('option');
+        $qb->where('option.key = :key');
+        
+        if ($active === true){
+            $qb->andWhere('option.active = true');
+        }
+        
+        if ($includeParents === false) {
+            $qb->andWhere('option.parent IS NOT NULL');
+            
+            if ($active === TRUE) {
+                $qb->join('option.parent', 'p');
+                $qb->andWhere('p.active = true');
+            }
+        }
+        
+        $qb->setParameter('key', $key);
+        
+        return $qb->getQuery()->getResult();
+    }
+    
+    /**
+     * 
+     * @return string[]
+     */
+    public function getKeys()
+    {
+        $keys = $this->createQueryBuilder('option')
+                ->select('option.key')
+                ->distinct()
+                ->getQuery()
+                ->getScalarResult();
+        
+        return array_map(function($r) {
+            return $r['key'];
+        }, $keys);
+    }
+    
+}