templates/hooks--*: remove sample hooks without any functionality

Remove the sample post-commit and post-receive hooks.  The sample
post-commit doesn't contain any sample functionality and the comments do
not provide more information than already found in the documentation.
The sample post-receive hooks doesn't provide any sample functionality
either and refers in the comments to a contrib hook that might be
installed in different locations on different systems, which isn't that
helpful.
Signed-off-by: NGerrit Pape <pape@smarden.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

templates/hooks--post-commit.sample

-#!/bin/sh
-#
-# An example hook script that is called after a successful
-# commit is made.
-#
-# To enable this hook, rename this file to "post-commit".
-
-: Nothing

templates/hooks--post-receive.sample

-#!/bin/sh
-#
-# An example hook script for the "post-receive" event.
-#
-# The "post-receive" script is run after receive-pack has accepted a pack
-# and the repository has been updated.  It is passed arguments in through
-# stdin in the form
-#  <oldrev> <newrev> <refname>
-# For example:
-#  aa453216d1b3e49e7f6f98441fa56946ddcd6a20 68f7abf4e6f922807889f52bc043ecd31b79f814 refs/heads/master
-#
-# see contrib/hooks/ for a sample, or uncomment the next line and
-# rename the file to "post-receive".
-
-#. /usr/share/doc/git-core/contrib/hooks/post-receive-email