Merge pull request #1659 by @rzhxeo

Add support for http://www.tube8.com

diff --combined youtube_dl/extractor/__init__.py
index d78014683a0d382e110ebaa32dbd288104507921,84fc2e4fac35c5707e26d5077b91cfdef4937bbe..0d933986f10af717befe791eb4565ab40c5f48b7
--- 1/youtube_dl/extractor/__init__.py
--- 2/youtube_dl/extractor/__init__.py
+++ b/youtube_dl/extractor/__init__.py
@@@ -72,7 -72,6 +72,7 @@@ from .jeuxvideo import JeuxVideoI
  from .jukebox import JukeboxIE
  from .justintv import JustinTVIE
  from .kankan import KankanIE
 +from .keezmovies import KeezMoviesIE
  from .kickstarter import KickStarterIE
  from .keek import KeekIE
  from .liveleak import LiveLeakIE
@@@ -95,7 -94,6 +95,7 @@@ from .ooyala import OoyalaI
  from .orf import ORFIE
  from .pbs import PBSIE
  from .photobucket import PhotobucketIE
 +from .pornhub import PornHubIE
  from .pornotube import PornotubeIE
  from .rbmaradio import RBMARadioIE
  from .redtube import RedTubeIE
@@@ -111,7 -109,6 +111,7 @@@ from .slideshare import SlideshareI
  from .sohu import SohuIE
  from .soundcloud import SoundcloudIE, SoundcloudSetIE, SoundcloudUserIE
  from .southparkstudios import SouthParkStudiosIE
 +from .spankwire import SpankwireIE
  from .spiegel import SpiegelIE
  from .stanfordoc import StanfordOpenClassroomIE
  from .statigram import StatigramIE
@@@ -124,6 -121,7 +124,7 @@@ from .tf1 import TF1I
  from .thisav import ThisAVIE
  from .traileraddict import TrailerAddictIE
  from .trilulilu import TriluliluIE
+ from .tube8 import Tube8IE
  from .tudou import TudouIE
  from .tumblr import TumblrIE
  from .tutv import TutvIE