Refactor ipautil.run
    
    The ipautil.run function now returns an object with returncode and
    output are accessible as attributes.
    
    The stdout and stderr of all commands are logged (unless skip_output is given).
    
    The stdout/stderr contents must be explicitly requested with a keyword
    argument, otherwise they are None.
    This is because in Python 3, the output needs to be decoded, and that can
    fail if it's not decodable (human-readable) text.
    
    The raw (bytes) output is always available from the result object,
    as is "leniently" decoded output suitable for logging.
    
    All calls are changed to reflect this.
    
    A use of Popen in cainstance is changed to ipautil.run.
    
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>