[liveleak] Adds support for thumbnails and updates tests
diff --git a/youtube_dl/extractor/liveleak.py b/youtube_dl/extractor/liveleak.py
index 29fba5f30b0..ea0565ac050 100644
--- a/youtube_dl/extractor/liveleak.py
+++ b/youtube_dl/extractor/liveleak.py
@@ -17,7 +17,8 @@ class LiveLeakIE(InfoExtractor):
             'ext': 'flv',
             'description': 'extremely bad day for this guy..!',
             'uploader': 'ljfriel2',
-            'title': 'Most unlucky car accident'
+            'title': 'Most unlucky car accident',
+            'thumbnail': 're:^https?://.*\.jpg$'
         }
     }, {
         'url': 'http://www.liveleak.com/view?i=f93_1390833151',
@@ -28,6 +29,7 @@ class LiveLeakIE(InfoExtractor):
             'description': 'German Television Channel NDR does an exclusive interview with Edward Snowden.\r\nUploaded on LiveLeak cause German Television thinks the rest of the world isn\'t intereseted in Edward Snowden.',
             'uploader': 'ARD_Stinkt',
             'title': 'German Television does first Edward Snowden Interview (ENGLISH)',
+            'thumbnail': 're:^https?://.*\.jpg$'
         }
     }, {
         'url': 'http://www.liveleak.com/view?i=4f7_1392687779',
@@ -49,7 +51,8 @@ class LiveLeakIE(InfoExtractor):
             'ext': 'mp4',
             'description': 'Happened on 27.7.2014. \r\nAt 0:53 you can see people still swimming at near beach.',
             'uploader': 'bony333',
-            'title': 'Crazy Hungarian tourist films close call waterspout in Croatia'
+            'title': 'Crazy Hungarian tourist films close call waterspout in Croatia',
+            'thumbnail': 're:^https?://.*\.jpg$'
         }
     }]
 
@@ -72,6 +75,7 @@ def _real_extract(self, url):
         age_limit = int_or_none(self._search_regex(
             r'you confirm that you are ([0-9]+) years and over.',
             webpage, 'age limit', default=None))
+        video_thumbnail = self._og_search_thumbnail(webpage)
 
         sources_raw = self._search_regex(
             r'(?s)sources:\s*(\[.*?\]),', webpage, 'video URLs', default=None)
@@ -124,4 +128,5 @@ def _real_extract(self, url):
             'uploader': video_uploader,
             'formats': formats,
             'age_limit': age_limit,
+            'thumbnail': video_thumbnail,
         }

Added support for fetching the video thumbnails, the only issue is concerning the third extractor test. When I run youtube-dl on that url using the --get-thumbnail flag it warns me that it is falling back to the default extractor. I'm not sure if this is an issue with the extractor or if this is expected. I didn't add the thumbnail url into that test but it seems the rest work just fine. 
