[nuevo] Generalize nuevo extractor and add support for trollvids

Supports only the nuevo player for now (most common).

[trollvids] convert duration to an int

[trollvids] added a test

[trollvids] made flake8 shut up

Generalized the Nuevo extractor

Affects: anitube, trollvids, trutube

[nuevo] Complied with the code comments.

youtube_dl/extractor/nuevo.py

@@ -0,0 +1,37 @@
+# encoding: utf-8
+from __future__ import unicode_literals
+
+from .common import InfoExtractor
+
+from ..utils import (
+    float_or_none,
+    xpath_text
+)
+
+
+class NuevoBaseIE(InfoExtractor):
+    def _extract_nuevo(self, config_url, video_id):
+        tree = self._download_xml(config_url, video_id, transform_source=lambda s: s.strip())
+
+        title = xpath_text(tree, './title')
+        if title:
+            title = title.strip()
+
+        thumbnail = xpath_text(tree, './image')
+        duration = float_or_none(xpath_text(tree, './duration'))
+
+        formats = []
+        for element_name, format_id in (('file', 'sd'), ('filehd', 'hd')):
+            video_url = tree.find(element_name)
+            video_url is None or formats.append({
+                'format_id': format_id,
+                'url': video_url.text
+            })
+
+        return {
+            'id': video_id,
+            'title': title,
+            'thumbnail': thumbnail,
+            'duration': duration,
+            'formats': formats
+        }