littletable 2.1.2

• Added json_encoder argument to Table.json_export, so that custom data fields can get exported without raising JSONEncodeError. peps.py example has been modified to demonstrate this. The json_encoder argument can take a single JSONEncoder subclass, or a tuple of subclasses, to be tried in sequence. Each should follow the pattern given in the online Python docs for the json module. (See updated code in examples/peps.py to see a custom JSONEncoder.)

  Also added json_decoder argument to Table.json_import, though it only supports passing a single class.