Prompt for tor controller password if needed

We use getpass for this (i.e. text mode).
This means that if you have password protection for your
Tor controller (advised) and you want to run onionshare-gui,
you need to do it from a terminal (so that you can enter
the password).

onionshare/onionshare.py

@@ -21,6 +21,7 @@ import os, sys, subprocess, time, argparse, inspect, shutil, socket, threading,
 import socks
 
 from stem.control import Controller
+from stem.connection import MissingPassword, AuthenticationFailure
 from stem import SocketError
 
 import strings, helpers, web
@@ -101,7 +102,17 @@ class OnionShare(object):
                         pass
                 if not controller:
                     raise NoTor(strings._("cant_connect_ctrlport").format(tor_control_ports))
-                controller.authenticate()
+                try:
+                    controller.authenticate()
+                except MissingPassword:  # We need a password for control port
+                    from getpass import getpass
+                    authed = False
+                    while not authed:
+                        try:
+                            controller.authenticate(getpass('Tor control password: '))
+                            authed = True
+                        except AuthenticationFailure:
+                            pass
 
                 # set up hidden service
                 controller.set_options([