rewrite bin/tar-entry.sh

We rewrote the `bin/tar-entry.sh` algorithm so that we do NOT have
to require Linux to produce a compressed tarball that is byte-for-byte
identical to a macOS compressed tarball for the same entry.

Changed `bin/tar-entry.sh` VERSION from "1.2 2024-03-22"
to "1.3 2024-03-25".

Added `bin/untar-entry.sh` to untar an entry from the
compressed tarball.

Added `make untar_entry_tarball` to untar all entry files.

Added `make untar_year_tarball` and `make untar_all_tarball`
stub Makefile rules.  The core it referred to does not yet exist.

Updated IOCCC manifest.  Updated `.entry.json` for `2004/sds`.

Performed `make www` to update web pages.  In most cases the
entry `index.html` added an inventory link for the new `.tar.tstamp` file.

Performed `form_entry_tarball` to complete the test of the above.

TODO: Test the results under Linux.

TODO: Update `bin/tar-year.sh`.  Update year level compressed tarballs.

TODO: Update `bin/tar-all.sh`.  Update top level compressed tarball.

TODO: Write `bin/untar-year.sh` and `bin/untar-all.sh`.

2004/sds/.entry.json

@@ -41,6 +41,14 @@
 	    "display_via_github" : true,
 	    "entry_text" : "how to run"
 	},
+	{
+	    "file_path" : "README_sds.txt",
+	    "inventory_order" : 200,
+	    "OK_to_edit" : true,
+	    "display_as" : "test",
+	    "display_via_github" : true,
+	    "entry_text" : "sample data used by try.sh"
+	},
 	{
 	    "file_path" : "2004_sds.tar.bz2",
 	    "inventory_order" : 100000,