v1.6.0 compatible w/2.6, sends failed response when no response is returned.

-> Modified all private members/functions to be prefixed with 1 underscore instead of 2.
-> Modified a couple of prints in connection_manager to be compatible with python 2.6.
-> Modified the _Execute method in BB.py to create a "failure" response when no response
    (or an object of a class different than Response) is returned.
-> Generated distribution 1.6.0.