status_result_t::la and dnet_id::id is available  to use in python

Implemented class python_dnet_id, which provides id as a python bytearray
python_key_t class is inherited from key_t and can be constructed by python_dnet_id
Implemented the set of array_to_boost_tuple functions with boost.preprocessor
Provides status_result_t::la as a tuple with array_to_boost_tuple functions
All properties in the status_result_t is now readonly
Prototypes of key_(str|repr) functions were changed to be related with new python_key_t