Merge pull request #1677 from rzhxeo/xtube

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

youtube_dl/extractor/__init__.py

@@ -153,6 +153,7 @@ from .worldstarhiphop import WorldStarHipHopIE
 from .xhamster import XHamsterIE
 from .xnxx import XNXXIE
 from .xvideos import XVideosIE
+from .xtube import XTubeIE
 from .yahoo import YahooIE, YahooSearchIE
 from .youjizz import YouJizzIE
 from .youku import YoukuIE