Final bag of small changes coming from distutils2.

- minor cleanup in Metadata
- trigger creation of the sysconfig._CONFIG_VARS dict
- home_page is used over home-page: it’s not a compound word, it’s an
  escaped space

Distutils2 is now synchronized with Packaging.
diff --git a/Lib/packaging/compat.py b/Lib/packaging/compat.py
index a82efd3..dcb58f5 100644
--- a/Lib/packaging/compat.py
+++ b/Lib/packaging/compat.py
@@ -1,8 +1,4 @@
-"""Compatibility helpers.
-
-This module provides classes, variables and imports which are used to
-support packaging across Python 2.x and 3.x.
-"""
+"""Compatibility helpers."""
 
 from packaging import logger
 
@@ -10,8 +6,6 @@
 # XXX Having two classes with the same name is not a good thing.
 # XXX 2to3-related code should move from util to this module
 
-# TODO Move common code here: PY3 (bool indicating if we're on 3.x), any, etc.
-
 try:
     from packaging.util import Mixin2to3 as _Mixin2to3
     _CONVERT = True