Order youtube search results by relevance rather than rating.

This makes the searches almost exactly match the website, and it's been requested enough that I think this change is worth doing.  Thanks to Dave Brown on the list for posting about how he had done this to good effect.

mythtv/programs/scripts/internetcontent/nv_python_libs/youtube/youtube_api.py

@@ -183,7 +183,7 @@ def __init__(self,
         self.config[u'urls'] = {}
 
         # v2 api calls - An example that must be customized for each target site
-        self.config[u'urls'][u'video.search'] = 'http://gdata.youtube.com/feeds/api/videos?vq=%s&max-results=%s&start-index=%s&orderby=rating&Ir=%s'
+        self.config[u'urls'][u'video.search'] = 'http://gdata.youtube.com/feeds/api/videos?vq=%s&max-results=%s&start-index=%s&orderby=relevance&Ir=%s'
 
 
         # Functions that parse video data from RSS data