Improve several stubs. (math, _random, time, etc.)

Some of these are derived from mypy/stubs/.

2.7/thread.pyi

@@ -1,40 +1,18 @@
-"""Stub file for the 'thread' module."""
-# This is an autogenerated file. It serves as a starting point
-# for a more precise manual annotation of this module.
-# Feel free to edit the source below, but remove this header when you do.
-
-from typing import Any, List, Tuple, Dict, GenericType
-
-LockType = ...  # type: lock
-error = ...  # type: object
+from typing import Callable, Any
 
 def _count() -> int: ...
 
-def allocate() -> lock: ...
-
-def allocate_lock() -> lock: ...
-
-def exit() -> Any:
-    raise SystemExit()
-
-def exit_thread() -> Any:
-    raise SystemExit()
-
-def get_ident() -> int: ...
-
-def interrupt_main() -> None: ...
-
-def stack_size(*args, **kwargs) -> int:
-    raise ValueError()
-
-def start_new(*args, **kwargs) -> int:
-    raise MemoryError()
-    raise TypeError()
-
-def start_new_thread(*args, **kwargs) -> int:
-    raise MemoryError()
-    raise TypeError()
+class error(Exception): ...
 
+class LockType:
+    def acquire(self, waitflag: int = None) -> bool: ...
+    def acquire_lock(self, waitflag: int = None) -> bool: ...
+    def release(self) -> None: ...
+    def release_lock(self) -> None: ...
+    def locked(self) -> bool: ...
+    def locked_lock(self) -> bool: ...
+    def __enter__(self) -> LockType: ...
+    def __exit__(self, value: Any, traceback: Any) -> None: ...
 
 class _local(object):
     pass
@@ -42,12 +20,13 @@ class _local(object):
 class _localdummy(object):
     pass
 
-class lock(object):
-    def __enter__(*args, **kwargs) -> bool: ...
-    def __exit__(*args, **kwargs) -> None: ...
-    def acquire(*args, **kwargs) -> bool: ...
-    def acquire_lock(*args, **kwargs) -> bool: ...
-    def locked() -> bool: ...
-    def locked_lock() -> bool: ...
-    def release() -> None: ...
-    def release_lock() -> None: ...
+def start_new(function: Callable[..., Any], args: Any, kwargs: Any = None) -> int: ...
+def start_new_thread(function: Callable[..., Any], args: Any, kwargs: Any = None) -> int: ...
+def interrupt_main() -> None: ...
+def exit() -> None: ...
+    raise SystemExit()
+def exit_thread() -> Any:
+    raise SystemExit()
+def allocate_lock() -> LockType: ...
+def get_ident() -> int: ...
+def stack_size(size: int = None) -> int: ...