modify : colors auth version

1. In auth.py .I think that since the two functions use the 'env' and 'join_host_strings', can be taken out of the module

2. In colors.py. In fact the bold can  use:  0:% s and 1:% s defined

3. In version.py.  when you use 'get_version', no longer need to determine that variable 'sha' results, you can return an exception when it is defined as ""