Call the init of super class in File

This allows proper handling of object oriented inheritance in derivative classes.

bob/db/base/file.py

@@ -13,7 +13,7 @@ class File(object):
   properties.
   """
 
-  def __init__(self, path, file_id=None):
+  def __init__(self, path, file_id=None, **kwargs):
     """**Constructor Documentation**
 
     Initialize the File object with the minimum required data.
@@ -53,6 +53,8 @@ class File(object):
             "'id' member variable in the derived class that is automatically "
             "determined (e.g. by SQLite)")
 
+    super(File, self).__init__(**kwargs)
+
   def __lt__(self, other):
     """This function defines the order on the File objects. File objects are
     always ordered by their ID, in ascending order."""