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

Some of these are derived from mypy/stubs/.

2.7/zlib.pyi

@@ -1,31 +1,36 @@
-"""Stub file for the 'zlib' 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.
+# Stubs for zlib (Python 2.7)
 
-from typing import Any, List, Tuple, Dict, GenericType
+class error(Exception): ...
 
-def adler32(a, *args, **kwargs) -> int: ...
+DEFLATED = ... # type: int
+DEF_MEM_LEVEL = ... # type: int
+MAX_WBITS = ... # type: int
+ZLIB_VERSION = ... # type: str
+Z_BEST_COMPRESSION = ... # type: int
+Z_BEST_SPEED = ... # type: int
+Z_DEFAULT_COMPRESSION = ... # type: int
+Z_DEFAULT_STRATEGY = ... # type: int
+Z_FILTERED = ... # type: int
+Z_FINISH = ... # type: int
+Z_FULL_FLUSH = ... # type: int
+Z_HUFFMAN_ONLY = ... # type: int
+Z_NO_FLUSH = ... # type: int
+Z_SYNC_FLUSH = ... # type: int
 
-def compress(a, *args, **kwargs) -> str:
-    raise MemoryError()
+def adler32(data: str, value: int = ...) -> int: ...
+def compress(data: str, level: int = ...) -> str: ...
+def crc32(data: str, value: int = ...) -> int: ...
+def decompress(data: str, wbits: int = ..., bufsize: int = ...) -> str: ...
 
-def compressobj(*args, **kwargs) -> Any:
-    raise MemoryError()
-    raise ValueError()
+class compressobj:
+    def __init__(level: int = ..., method: int = ..., wbits: int = ..., memlevel: int = ...,
+                 strategy: int = ...): ...
+    def compress(self, data: str) -> str
+    def copy(self) -> _Compress
+    def flush(self) -> NoneType
 
-def crc32(a, *args, **kwargs) -> int: ...
-
-def decompress(a, *args, **kwargs) -> str:
-    raise MemoryError()
-
-def decompressobj(*args, **kwargs) -> Any:
-    raise MemoryError()
-    raise ValueError()
-
-
-class Compress(object):
-    pass
-
-class Decompress(object):
-    pass
+class decompressobj:
+    def __init__(wbits: int = ...): ...
+    def copy(self) -> _Compress
+    def decompress(self, data: str) -> str
+    def flush(self) -> NoneType