Add types for gettext (#217)

* Add empty stubs for gettext Translations subclasses

GNUTranslations and NullTranslations do not add any methods to the base
Translations class, so remove the TODO comment and just declare the
classes.

* Add missing types for py3 gettext.

stdlib/3/gettext.pyi

@@ -1,39 +1,44 @@
 # Stubs for gettext (Python 3.4)
-#
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
 
-from typing import Any
+from typing import Any, IO, List, Optional, Union, Callable
 
 class NullTranslations:
-    def __init__(self, fp=...) -> None: ...
-    def add_fallback(self, fallback): ...
-    def gettext(self, message): ...
-    def lgettext(self, message): ...
-    def ngettext(self, msgid1, msgid2, n): ...
-    def lngettext(self, msgid1, msgid2, n): ...
-    def info(self): ...
-    def charset(self): ...
-    def output_charset(self): ...
-    def set_output_charset(self, charset): ...
-    def install(self, names=...): ...
+    def __init__(self, fp: IO[str] = ...) -> None: ...
+    def add_fallback(self, fallback: NullTranslations) -> None: ...
+    def gettext(self, message: str) -> str: ...
+    def lgettext(self, message: str) -> str: ...
+    def ngettext(self, singular: str, plural: str, n: int) -> str: ...
+    def lngettext(self, singular: str, plural: str, n: int) -> str: ...
+    def info(self) -> Any: ...
+    def charset(self) -> Any: ...
+    def output_charset(self) -> Any: ...
+    def set_output_charset(self, charset: Any) -> None: ...
+    def install(self, names: List[str] = ...) -> None: ...
 
 class GNUTranslations(NullTranslations):
-    LE_MAGIC = ...  # type: Any
-    BE_MAGIC = ...  # type: Any
-    def lgettext(self, message): ...
-    def lngettext(self, msgid1, msgid2, n): ...
-    def gettext(self, message): ...
-    def ngettext(self, msgid1, msgid2, n): ...
+    LE_MAGIC = ...  # type: int
+    BE_MAGIC = ...  # type: int
 
-def find(domain, localedir=..., languages=..., all=...): ...
-def translation(domain, localedir=..., languages=..., class_=..., fallback=...,
-                codeset=...): ...
-def install(domain, localedir=..., codeset=..., names=...): ...
-def textdomain(domain=...): ...
-def bindtextdomain(domain, localedir=...): ...
-def dgettext(domain, message): ...
-def dngettext(domain, msgid1, msgid2, n): ...
-def gettext(message): ...
-def ngettext(msgid1, msgid2, n): ...
+def find(domain: str, localedir: str = ..., languages: List[str] = ...,
+         all: bool = ...): ...
 
-Catalog = ...  # type: Any
+def translation(domain: str, localedir: str = ..., languages: List[str] = ...,
+                class_: Callable[[IO[str]], NullTranslations] = ...,
+                fallback: bool =... , codeset: Any = ...) -> NullTranslations: ...
+
+def install(domain: str, localedir: str = ..., codeset: Any = ...,
+            names: List[str] = ...): ...
+
+def textdomain(domain: str = ...) -> str: ...
+def bindtextdomain(domain: str, localedir: str = ...) -> str: ...
+def bind_textdomain_codeset(domain: str, codeset: str = ...) -> str: ...
+def dgettext(domain: str, message: str) -> str: ...
+def ldgettext(domain: str, message: str) -> str: ...
+def dngettext(domain: str, singular: str, plural: str, n: int) -> str: ...
+def ldngettext(domain: str, singular: str, plural: str, n: int) -> str: ...
+def gettext(message: str) -> str: ...
+def lgettext(message: str) -> str: ...
+def ngettext(singular: str, plural: str, n: int) -> str: ...
+def lngettext(singular: str, plural: str, n: int) -> str: ...
+
+Catalog = translation