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/py.py

@@ -0,0 +1,67 @@
+from __future__ import absolute_import, division, unicode_literals
+from six import text_type
+
+from bisect import bisect_left
+
+from ._base import Trie as ABCTrie
+
+
+class Trie(ABCTrie):
+    def __init__(self, data):
+        if not all(isinstance(x, text_type) for x in data.keys()):
+            raise TypeError("All keys must be strings")
+
+        self._data = data
+        self._keys = sorted(data.keys())
+        self._cachestr = ""
+        self._cachepoints = (0, len(data))
+
+    def __contains__(self, key):
+        return key in self._data
+
+    def __len__(self):
+        return len(self._data)
+
+    def __iter__(self):
+        return iter(self._data)
+
+    def __getitem__(self, key):
+        return self._data[key]
+
+    def keys(self, prefix=None):
+        if prefix is None or prefix == "" or not self._keys:
+            return set(self._keys)
+
+        if prefix.startswith(self._cachestr):
+            lo, hi = self._cachepoints
+            start = i = bisect_left(self._keys, prefix, lo, hi)
+        else:
+            start = i = bisect_left(self._keys, prefix)
+
+        keys = set()
+        if start == len(self._keys):
+            return keys
+
+        while self._keys[i].startswith(prefix):
+            keys.add(self._keys[i])
+            i += 1
+
+        self._cachestr = prefix
+        self._cachepoints = (start, i)
+
+        return keys
+
+    def has_keys_with_prefix(self, prefix):
+        if prefix in self._data:
+            return True
+
+        if prefix.startswith(self._cachestr):
+            lo, hi = self._cachepoints
+            i = bisect_left(self._keys, prefix, lo, hi)
+        else:
+            i = bisect_left(self._keys, prefix)
+
+        if i == len(self._keys):
+            return False
+
+        return self._keys[i].startswith(prefix)