Add Python 3 modules, and more Python 2 modules.

Also, sort names alphabetically and add module docstrings.

python2/_collections.py

@@ -0,0 +1,39 @@
+"""Stub file for the '_collections' module."""
+# This is an autogenerated file. It serves as a starting point
+# for a more percise manual annotation of this module.
+# Feel free to edit the source below, but remove this header when you do.
+
+class defaultdict(object):
+    def __copy__() -> object: pass
+    def __missing__(*args, **kwargs) -> object:
+        raise KeyError()
+    def __reduce__() -> tuple: pass
+    def copy() -> object: pass
+
+class deque(object):
+    def __copy__() -> object: pass
+    def __reduce__() -> tuple: pass
+    def __reversed__() -> object: pass
+    def __sizeof__() -> long: pass
+    def append(*args, **kwargs) -> NoneType: pass
+    def appendleft(*args, **kwargs) -> NoneType: pass
+    def clear() -> NoneType: pass
+    def count(*args, **kwargs) -> int:
+        raise RuntimeError()
+    def extend(*args, **kwargs) -> NoneType: pass
+    def extendleft(*args, **kwargs) -> NoneType: pass
+    def pop() -> object:
+        raise IndexError()
+    def popleft() -> object:
+        raise IndexError()
+    def remove(*args, **kwargs) -> NoneType:
+        raise ValueError()
+        raise IndexError()
+    def reverse() -> NoneType: pass
+    def rotate(*args, **kwargs) -> NoneType: pass
+
+class deque_iterator(object):
+    def __length_hint__() -> int: pass
+
+class deque_reverse_iterator(object):
+    def __length_hint__() -> int: pass