#1286 Remove header comments from stubs (#1292)

- Updates documentation related to previously required comment headers.
- Removes all comment headers from stubs
- Occasionally included a header for stubs that were noted to be incomplete or contained todo's.

stdlib/2and3/xml/__init__.pyi

@@ -1,7 +1,3 @@
-# Stubs for xml.sax (Python 3)
-#
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
-
 class SAXException(Exception):
     def __init__(self, msg, exception=None): ...
     def getMessage(self): ...

stdlib/2and3/xml/sax/handler.pyi

@@ -1,7 +1,3 @@
-# Stubs for xml.sax.handler (Python 2)
-#
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
-
 from typing import Any
 
 version = ...  # type: Any

stdlib/2and3/xml/sax/saxutils.pyi

@@ -1,7 +1,3 @@
-# Stubs for xml.sax.saxutils (Python 2)
-#
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
-
 from typing import Mapping
 
 from xml.sax import handler

stdlib/2and3/xml/sax/xmlreader.pyi

@@ -1,7 +1,3 @@
-# Stubs for xml.sax.xmlreader (Python 2)
-#
-# NOTE: This dynamically typed stub was automatically generated by stubgen.
-
 class XMLReader:
     def __init__(self) -> None: ...
     def parse(self, source): ...