pg()
  PostgreSQL support via pg python module.
  
  Requires: pg python module
  
  Usage: db.pg(host='127.0.0.1',port=5432,dbname='sagator',
               dbuser='sagator',dbpasswd='xxxxxx')
  
  Parameters:
        host            - database server hostname
        port            - tcp socket port for database server
        dbname          - database name
        dbuser          - authorization username
        dbpasswd        - authorization password
  
  Database creation script:     scripts/db/pgsql.sh