Merge branch '3.0.x' into 3.1.x

Conflicts:
	Resources/config/orm.xml

Author: stof

Resources/config/mongodb.xml

@@ -29,7 +29,7 @@
             <argument /> <!-- object persister -->
             <argument type="service" id="fos_elastica.indexable" />
             <argument type="collection" /> <!-- configuration -->
-            <argument /> <!-- logger -->
+            <argument>null</argument> <!-- logger -->
         </service>
 
         <service id="fos_elastica.elastica_to_model_transformer.prototype.mongodb" class="%fos_elastica.elastica_to_model_transformer.prototype.mongodb.class%" public="false" abstract="true">

Resources/config/orm.xml

@@ -29,7 +29,7 @@
             <argument /> <!-- object persister -->
             <argument type="service" id="fos_elastica.indexable" />
             <argument type="collection" /> <!-- configuration -->
-            <argument on-invalid="null" /> <!-- logger -->
+            <argument>null</argument> <!-- logger -->
         </service>
 
         <service id="fos_elastica.elastica_to_model_transformer.prototype.orm" class="%fos_elastica.elastica_to_model_transformer.prototype.orm.class%" public="false" abstract="true">