first variant of the object model
expand the model to use attributes instead of messages
first draft of customizations

implement __getattr__ support
more realistic example
an actual test and fix for __get__
remove line
also support __setattr__
implement maps
description of the stages
a note about loc
consistency across the stages
two scripts that make dealing with the stages easier
do the method binding in read_field
use a sentinel insead of exceptions internally
rename _dct to _fields
change read/write_field to read/write_attr

add docstring to _read/_write_dict
cls cannot be None any more in the Instance constructor
use Base constructor
works on python 2.7 and 3.3
remove copy-paste leftover