Merge binascii module into 2and3 (#1144)

* Unify binascii module

* Move binascii to 2and3

* CR fixes

* Fix flakes

* Fix flakes better

stdlib/2and3/binascii.pyi

@@ -0,0 +1,45 @@
+# Stubs for binascii
+
+# Based on http://docs.python.org/3.2/library/binascii.html
+
+import sys
+from typing import Union, Text
+
+
+if sys.version_info < (3,):
+    # Python 2 accepts unicode ascii pretty much everywhere.
+    _Bytes = Union[bytes, Text]
+    _Ascii = Union[bytes, Text]
+elif sys.version_info < (3, 3):
+    # Python 3.2 and below only accepts bytes.
+    _Bytes = bytes
+    _Ascii = bytes
+else:
+    # But since Python 3.3 ASCII-only unicode strings are accepted by the
+    # a2b_* functions.
+    _Bytes = bytes
+    _Ascii = Union[bytes, Text]
+
+def a2b_uu(string: _Ascii) -> bytes: ...
+def b2a_uu(data: _Bytes) -> bytes: ...
+def a2b_base64(string: _Ascii) -> bytes: ...
+if sys.version_info >= (3, 6):
+    def b2a_base64(data: _Bytes, *, newline: bool = ...) -> bytes: ...
+else:
+    def b2a_base64(data: _Bytes) -> bytes: ...
+def a2b_qp(string: _Ascii, header: bool = ...) -> bytes: ...
+def b2a_qp(data: _Bytes, quotetabs: bool = ..., istext: bool = ...,
+             header: bool = ...) -> bytes: ...
+def a2b_hqx(string: _Ascii) -> bytes: ...
+def rledecode_hqx(data: _Bytes) -> bytes: ...
+def rlecode_hqx(data: _Bytes) -> bytes: ...
+def b2a_hqx(data: _Bytes) -> bytes: ...
+def crc_hqx(data: _Bytes, crc: int) -> int: ...
+def crc32(data: _Bytes, crc: int = ...) -> int: ...
+def b2a_hex(data: _Bytes) -> bytes: ...
+def hexlify(data: _Bytes) -> bytes: ...
+def a2b_hex(hexstr: _Ascii) -> bytes: ...
+def unhexlify(hexlify: _Ascii) -> bytes: ...
+
+class Error(Exception): ...
+class Incomplete(Exception): ...