* postgresql_user module - transaction logic hacks to allow recovery from failed select
* postgresql_user - PEP8 and style fixes to make debugging easier
* postgresql_user - move password changing logic to separate function
* postgresql_user - trap failure in case where there is no access to pg_authid
* postgresql_user - further PEP8 fixes
* postgresql_user - Simplify password change logic and improve imports according to suggestions from PR review
* postgresql_user - Eliminate pep8/blank line errors introduced in merge
* Check behaviour when pg_authid relation isn't readable
TASK [postgresql : Normal user isn't allowed to access pg_authid relation:
password comparison will fail, password will be updated] ***
An exception occurred during task execution. To see the full traceback,
use -vvv. The error was: psycopg2.ProgrammingError: permission denied
for relation pg_authid
* Don't reintroduce passlib, remove useless query
