Remove the --max-quality option

It doesn't work well with 'bestvideo' and 'bestaudio' because they are usually before the max quality.
Format filters should be used instead, they are more flexible and don't require the requested quality to exist for each video.

test/parameters.json

@@ -8,7 +8,6 @@
     "forcetitle": false, 
     "forceurl": false, 
     "format": "best",
-    "format_limit": null, 
     "ignoreerrors": false, 
     "listformats": null, 
     "logtostderr": false, 

test/test_YoutubeDL.py

@@ -101,39 +101,6 @@ class TestFormatSelection(unittest.TestCase):
         downloaded = ydl.downloaded_info_dicts[0]
         self.assertEqual(downloaded['ext'], 'flv')
 
-    def test_format_limit(self):
-        formats = [
-            {'format_id': 'meh', 'url': 'http://example.com/meh', 'preference': 1},
-            {'format_id': 'good', 'url': 'http://example.com/good', 'preference': 2},
-            {'format_id': 'great', 'url': 'http://example.com/great', 'preference': 3},
-            {'format_id': 'excellent', 'url': 'http://example.com/exc', 'preference': 4},
-        ]
-        info_dict = _make_result(formats)
-
-        ydl = YDL()
-        ydl.process_ie_result(info_dict)
-        downloaded = ydl.downloaded_info_dicts[0]
-        self.assertEqual(downloaded['format_id'], 'excellent')
-
-        ydl = YDL({'format_limit': 'good'})
-        assert ydl.params['format_limit'] == 'good'
-        ydl.process_ie_result(info_dict.copy())
-        downloaded = ydl.downloaded_info_dicts[0]
-        self.assertEqual(downloaded['format_id'], 'good')
-
-        ydl = YDL({'format_limit': 'great', 'format': 'all'})
-        ydl.process_ie_result(info_dict.copy())
-        self.assertEqual(ydl.downloaded_info_dicts[0]['format_id'], 'meh')
-        self.assertEqual(ydl.downloaded_info_dicts[1]['format_id'], 'good')
-        self.assertEqual(ydl.downloaded_info_dicts[2]['format_id'], 'great')
-        self.assertTrue('3' in ydl.msgs[0])
-
-        ydl = YDL()
-        ydl.params['format_limit'] = 'excellent'
-        ydl.process_ie_result(info_dict.copy())
-        downloaded = ydl.downloaded_info_dicts[0]
-        self.assertEqual(downloaded['format_id'], 'excellent')
-
     def test_format_selection(self):
         formats = [
             {'format_id': '35', 'ext': 'mp4', 'preference': 1, 'url': TEST_URL},