Small bug fixes

- Delete from Releases when deleting artist/album
- Searcher - Size limits not quite working
- Searcher - 1st newznab used even if disabled
- Rutracker search stopped working for me, fixed by updating Beautiful
Soup. Moved bs4 and html5lib to lib and ensured (I think) it’s imported
from the right place

lib/html5lib/trie/datrie.py

@@ -0,0 +1,44 @@
+from __future__ import absolute_import, division, unicode_literals
+
+from datrie import Trie as DATrie
+from six import text_type
+
+from ._base import Trie as ABCTrie
+
+
+class Trie(ABCTrie):
+    def __init__(self, data):
+        chars = set()
+        for key in data.keys():
+            if not isinstance(key, text_type):
+                raise TypeError("All keys must be strings")
+            for char in key:
+                chars.add(char)
+
+        self._data = DATrie("".join(chars))
+        for key, value in data.items():
+            self._data[key] = value
+
+    def __contains__(self, key):
+        return key in self._data
+
+    def __len__(self):
+        return len(self._data)
+
+    def __iter__(self):
+        raise NotImplementedError()
+
+    def __getitem__(self, key):
+        return self._data[key]
+
+    def keys(self, prefix=None):
+        return self._data.keys(prefix)
+
+    def has_keys_with_prefix(self, prefix):
+        return self._data.has_keys_with_prefix(prefix)
+
+    def longest_prefix(self, prefix):
+        return self._data.longest_prefix(prefix)
+
+    def longest_prefix_item(self, prefix):
+        return self._data.longest_prefix_item(prefix)