Added type annotations and small fixes (#219)

* json.loads() accepts unicode

* threading.BoundedSemaphore is subclass of Semaphore

* Added type annotations for logging/__init__.pyi and logging/handlers.pyi

* Changed style of variable declaration to fit the rest of the file

stdlib/2.7/threading.pyi

@@ -73,7 +73,7 @@ class Semaphore(object):
     def __enter__(self) -> bool: ...
     def __exit__(self, *args): ...
 
-class BoundedSemaphore(object):
+class BoundedSemaphore(Semaphore):
     def acquire(self, blocking: bool = ...) -> Optional[bool]: ...
     def release(self) -> None: ...
     def __init__(self, value: int = ...) -> None: ...