IDLE: Replace current goto dialog

GitHub fields:

assignee = 'https://github.com/terryjreedy'
closed_at = None
created_at = <Date 2017-05-31.08:02:16.542>
labels = ['expert-IDLE', 'type-feature', '3.7']
title = 'IDLE: Add navigate bar and replace current goto dialog'
updated_at = <Date 2017-06-06.06:58:08.746>
user = 'https://github.com/mlouielu'

bugs.python.org fields:

activity = <Date 2017-06-06.06:58:08.746>
actor = 'louielu'
assignee = 'terry.reedy'
closed = False
closed_date = None
closer = None
components = ['IDLE']
creation = <Date 2017-05-31.08:02:16.542>
creator = 'louielu'
dependencies = []
files = ['46925']
hgrepos = []
issue_num = 30521
keywords = []
message_count = 3.0
messages = ['294819', '295211', '295242']
nosy_count = 2.0
nosy_names = ['terry.reedy', 'louielu']
pr_nums = ['1884']
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue30521'
versions = ['Python 3.7']