doc: refer to internet archive

These pages are no longer reachable from their original locations,
which makes things difficult for readers. Instead, switch to linking to
the Internet Archive for the content.

Signed-off-by: Josh Soref <jsoref@gmail.com>

gitweb/gitweb.perl

@@ -8193,7 +8193,7 @@ sub git_feed {
 	my $have_blame = gitweb_check_feature('blame');
 
 	# Atom: http://www.atomenabled.org/developers/syndication/
-	# RSS:  http://www.notestips.com/80256B3A007F2692/1/NAMO5P9UPQ
+	# RSS:  https://web.archive.org/web/20030729001534/http://www.notestips.com/80256B3A007F2692/1/NAMO5P9UPQ
 	if ($format ne 'rss' && $format ne 'atom') {
 		die_error(400, "Unknown web feed format");
 	}

sha1dc/sha1.c

@@ -88,7 +88,7 @@
 /*
  * Should define Big Endian for a whitelist of known processors. See
  * https://sourceforge.net/p/predef/wiki/Endianness/ and
- * http://www.oracle.com/technetwork/server-storage/solaris/portingtosolaris-138514.html
+ * https://web.archive.org/web/20140421151132/http://www.perforce.com/perforce/doc.current/manuals/p4sag/chapter.superuser.html
  */
 #define SHA1DC_BIGENDIAN
 

t/lib-gpg.sh

@@ -13,7 +13,7 @@ test_lazy_prereq GPG '
 	gpg_version=$(gpg --version 2>&1)
 	test $? != 127 || exit 1
 
-	# As said here: http://www.gnupg.org/documentation/faqs.html#q6.19
+	# As said here: https://web.archive.org/web/20130212022238/https://www.gnupg.org/faq/gnupg-faq.html#why-does-gnupg-1.0.6-bail-out-on-keyrings-used-with-1.0.7
 	# the gpg version 1.0.6 did not parse trust packets correctly, so for
 	# that version, creation of signed tags using the generated key fails.
 	case "$gpg_version" in

t/t9816-git-p4-locked.sh

@@ -9,7 +9,7 @@ test_expect_success 'start p4d' '
 '
 
 # See
-# http://www.perforce.com/perforce/doc.current/manuals/p4sag/03_superuser.html#1088563
+# https://web.archive.org/web/20150602090517/http://www.perforce.com/perforce/doc.current/manuals/p4sag/chapter.superuser.html#superuser.basic.typemap_locking
 # for suggestions on how to configure "sitewide pessimistic locking"
 # where only one person can have a file open for edit at a time.
 test_expect_success 'init depot' '