plugins ext FEATURE initial schema-mount support

Only for XML data for now. Includes lots of other
changes needed to support this extension.
diff --git a/src/tree_schema.c b/src/tree_schema.c
index 076fa37..0b92e67 100644
--- a/src/tree_schema.c
+++ b/src/tree_schema.c
@@ -471,6 +471,7 @@
             }
         }
     }
+
     return NULL;
 }