upgraded distutils docs w.r.t. the manifest regeneration

Doc/distutils/sourcedist.rst

@@ -137,20 +137,12 @@ There are a couple of options that modify this behaviour.  First, use the
 :option:`--no-defaults` and :option:`--no-prune` to disable the standard
 "include" and "exclude" sets.
 
-Second, you might want to force the manifest to be regenerated---for example, if
-you have added or removed files or directories that match an existing pattern in
-the manifest template, you should regenerate the manifest::
-
-   python setup.py sdist --force-manifest
-
-Or, you might just want to (re)generate the manifest, but not create a source
-distribution::
+Second, you might just want to (re)generate the manifest, but not create a
+source distribution::
 
    python setup.py sdist --manifest-only
 
-:option:`--manifest-only` implies :option:`--force-manifest`. :option:`-o` is a
-shortcut for :option:`--manifest-only`, and :option:`-f` for
-:option:`--force-manifest`.
+:option:`-o` is a sortcut for :option:`--manifest-only`.
 
 .. _manifest_template:
 

Lib/distutils/command/sdist.py

@@ -63,7 +63,8 @@ class sdist(Command):
          "just regenerate the manifest and then stop "
          "(implies --force-manifest)"),
         ('force-manifest', 'f',
-         "forcibly regenerate the manifest and carry on as usual"),
+         "forcibly regenerate the manifest and carry on as usual. "
+         "Deprecated: now the manifest is always regenerated."),
         ('formats=', None,
          "formats for source distribution (comma-separated list)"),
         ('keep-temp', 'k',