* new module credentials.py which contains classes
and methods to set and get passwords for different
backends:
- python-keyring
- gnomekeyring
- ConfigFile based storage
The new code should be backward compatible except a minor
change in add_section (pass and passx are not removed from
the config parser). This affects only callers that do not pass
a creds_mgr_descriptor.
On initial osc call or initial osc call on new API Url
the user now can decide where to store the password (based
on the backends available on his system)
