ipaddress: Wrong behavior with ::ffff:1.2.3.4 style IPs

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-06-08.14:55:23.856>
labels = ['type-bug', 'library', 'docs']
title = 'ipaddress: Wrong behavior with ::ffff:1.2.3.4 style IPs'
updated_at = <Date 2017-05-23.00:08:58.753>
user = 'https://github.com/ThiefMaster'

bugs.python.org fields:

activity = <Date 2017-05-23.00:08:58.753>
actor = 'arp11'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation', 'Library (Lib)']
creation = <Date 2016-06-08.14:55:23.856>
creator = 'ThiefMaster'
dependencies = []
files = []
hgrepos = []
issue_num = 27269
keywords = []
message_count = 4.0
messages = ['267861', '269984', '269986', '294198']
nosy_count = 5.0
nosy_names = ['pmoody', 'docs@python', 'socketpair', 'ThiefMaster', 'arp11']
pr_nums = ['1741']
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue27269'
versions = ['Python 3.5', 'Python 3.6']