gnu: python2: Add upstream security fixes.

This addresses CVE-2018-{1060,1061,14647,1000802}.

* gnu/packages/patches/python2-CVE-2018-1000802.patch,
gnu/packages/patches/python2-CVE-2018-1060.patch,
gnu/packages/patches/python2-CVE-2018-1061.patch,
gnu/packages/patches/python2-CVE-2018-14647.patch: New files.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/python.scm (python-2/fixed): New variable.
(python-2.7)[replacement]: New field.
(python2-minimal): Use PACKAGE/INHERIT.

gnu/packages/patches/python2-CVE-2018-1000802.patch

@@ -0,0 +1,47 @@
+Fix CVE-2018-1000802:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-1000802
+
+Taken from upstream commit (sans NEWS):
+https://github.com/python/cpython/commit/d8b103b8b3ef9644805341216963a64098642435
+
+diff --git a/Lib/shutil.py b/Lib/shutil.py
+index 3462f7c5e9..0ab1a06f52 100644
+--- a/Lib/shutil.py
++++ b/Lib/shutil.py
+@@ -413,17 +413,21 @@ def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0,
+ 
+     return archive_name
+ 
+-def _call_external_zip(base_dir, zip_filename, verbose=False, dry_run=False):
++def _call_external_zip(base_dir, zip_filename, verbose, dry_run, logger):
+     # XXX see if we want to keep an external call here
+     if verbose:
+         zipoptions = "-r"
+     else:
+         zipoptions = "-rq"
+-    from distutils.errors import DistutilsExecError
+-    from distutils.spawn import spawn
++    cmd = ["zip", zipoptions, zip_filename, base_dir]
++    if logger is not None:
++        logger.info(' '.join(cmd))
++    if dry_run:
++        return
++    import subprocess
+     try:
+-        spawn(["zip", zipoptions, zip_filename, base_dir], dry_run=dry_run)
+-    except DistutilsExecError:
++        subprocess.check_call(cmd)
++    except subprocess.CalledProcessError:
+         # XXX really should distinguish between "couldn't find
+         # external 'zip' command" and "zip failed".
+         raise ExecError, \
+@@ -458,7 +462,7 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
+         zipfile = None
+ 
+     if zipfile is None:
+-        _call_external_zip(base_dir, zip_filename, verbose, dry_run)
++        _call_external_zip(base_dir, zip_filename, verbose, dry_run, logger)
+     else:
+         if logger is not None:
+             logger.info("creating '%s' and adding '%s' to it",