Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/@python2/Queue.pyi

@@ -0,0 +1,29 @@
+from collections import deque
+from typing import Any, Deque, Generic, Optional, TypeVar
+
+_T = TypeVar("_T")
+
+class Empty(Exception): ...
+class Full(Exception): ...
+
+class Queue(Generic[_T]):
+    maxsize: Any
+    mutex: Any
+    not_empty: Any
+    not_full: Any
+    all_tasks_done: Any
+    unfinished_tasks: Any
+    queue: Deque[Any]  # undocumented
+    def __init__(self, maxsize: int = ...) -> None: ...
+    def task_done(self) -> None: ...
+    def join(self) -> None: ...
+    def qsize(self) -> int: ...
+    def empty(self) -> bool: ...
+    def full(self) -> bool: ...
+    def put(self, item: _T, block: bool = ..., timeout: Optional[float] = ...) -> None: ...
+    def put_nowait(self, item: _T) -> None: ...
+    def get(self, block: bool = ..., timeout: Optional[float] = ...) -> _T: ...
+    def get_nowait(self) -> _T: ...
+
+class PriorityQueue(Queue[_T]): ...
+class LifoQueue(Queue[_T]): ...