Add dir_fd and follow_symlinks kwargs to os.listdir and os.scandir

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-05-22.17:53:26.298>
labels = ['type-feature', 'library']
title = 'Add dir_fd and follow_symlinks kwargs to os.listdir and os.scandir'
updated_at = <Date 2016-05-22.22:25:35.138>
user = 'https://bugs.python.org/abacabadabacaba'

bugs.python.org fields:

activity = <Date 2016-05-22.22:25:35.138>
actor = 'abacabadabacaba'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2016-05-22.17:53:26.298>
creator = 'abacabadabacaba'
dependencies = []
files = []
hgrepos = []
issue_num = 27084
keywords = []
message_count = 5.0
messages = ['266091', '266099', '266105', '266109', '266113']
nosy_count = 2.0
nosy_names = ['abacabadabacaba', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue27084'
versions = ['Python 3.6']