Packaging cleanup: remove conditionals for < 2.6 support.

PEP 370 features and sys.dont_write_bytecode are always available
in 3.3; the distutils2 backport still has the conditionals.

I also renamed an internal misnamed method and fixed a few things
(“packaging2” name, stray print, unused import, fd leak).
diff --git a/Lib/packaging/tests/test_command_build_ext.py b/Lib/packaging/tests/test_command_build_ext.py
index 59d09bf..52dfa31 100644
--- a/Lib/packaging/tests/test_command_build_ext.py
+++ b/Lib/packaging/tests/test_command_build_ext.py
@@ -18,18 +18,13 @@
                        support.LoggingCatcher,
                        unittest.TestCase):
     def setUp(self):
-        # Create a simple test environment
-        # Note that we're making changes to sys.path
         super(BuildExtTestCase, self).setUp()
         self.tmp_dir = self.mkdtemp()
         self.old_user_base = site.USER_BASE
         site.USER_BASE = self.mkdtemp()
 
     def tearDown(self):
-        # Get everything back to normal
-        if sys.version > "2.6":
-            site.USER_BASE = self.old_user_base
-
+        site.USER_BASE = self.old_user_base
         super(BuildExtTestCase, self).tearDown()
 
     def test_build_ext(self):
@@ -94,7 +89,6 @@
         # make sure we get some library dirs under solaris
         self.assertGreater(len(cmd.library_dirs), 0)
 
-    @unittest.skipIf(sys.version < '2.6', 'requires Python 2.6 or higher')
     def test_user_site(self):
         dist = Distribution({'name': 'xx'})
         cmd = build_ext(dist)
diff --git a/Lib/packaging/tests/test_command_build_py.py b/Lib/packaging/tests/test_command_build_py.py
index 243a863..4eeb34e 100644
--- a/Lib/packaging/tests/test_command_build_py.py
+++ b/Lib/packaging/tests/test_command_build_py.py
@@ -99,8 +99,6 @@
             os.chdir(cwd)
             sys.stdout = old_stdout
 
-    @unittest.skipUnless(hasattr(sys, 'dont_write_bytecode'),
-                         'sys.dont_write_bytecode not supported')
     def test_dont_write_bytecode(self):
         # makes sure byte_compile is not used
         pkg_dir, dist = self.create_dist()
diff --git a/Lib/packaging/tests/test_command_install_dist.py b/Lib/packaging/tests/test_command_install_dist.py
index 8f90aff..808b568 100644
--- a/Lib/packaging/tests/test_command_install_dist.py
+++ b/Lib/packaging/tests/test_command_install_dist.py
@@ -72,7 +72,6 @@
         check_path(cmd.install_scripts, os.path.join(destination, "bin"))
         check_path(cmd.install_data, destination)
 
-    @unittest.skipIf(sys.version < '2.6', 'requires Python 2.6 or higher')
     def test_user_site(self):
         # test install with --user
         # preparing the environment for the test
@@ -173,12 +172,11 @@
         cmd.home = 'home'
         self.assertRaises(PackagingOptionError, cmd.finalize_options)
 
-        if sys.version >= '2.6':
-            # can't combine user with with prefix/exec_prefix/home or
-            # install_(plat)base
-            cmd.prefix = None
-            cmd.user = 'user'
-            self.assertRaises(PackagingOptionError, cmd.finalize_options)
+        # can't combine user with with prefix/exec_prefix/home or
+        # install_(plat)base
+        cmd.prefix = None
+        cmd.user = 'user'
+        self.assertRaises(PackagingOptionError, cmd.finalize_options)
 
     def test_old_record(self):
         # test pre-PEP 376 --record option (outside dist-info dir)
diff --git a/Lib/packaging/tests/test_command_install_lib.py b/Lib/packaging/tests/test_command_install_lib.py
index b46f3bd..d36120b 100644
--- a/Lib/packaging/tests/test_command_install_lib.py
+++ b/Lib/packaging/tests/test_command_install_lib.py
@@ -7,13 +7,6 @@
 from packaging.compiler.extension import Extension
 from packaging.errors import PackagingOptionError
 
-try:
-    no_bytecode = sys.dont_write_bytecode
-    bytecode_support = True
-except AttributeError:
-    no_bytecode = False
-    bytecode_support = False
-
 
 class InstallLibTestCase(support.TempdirManager,
                          support.LoggingCatcher,
@@ -40,7 +33,7 @@
         cmd.finalize_options()
         self.assertEqual(cmd.optimize, 2)
 
-    @unittest.skipIf(no_bytecode, 'byte-compile not supported')
+    @unittest.skipIf(sys.dont_write_bytecode, 'byte-compile not supported')
     def test_byte_compile(self):
         pkg_dir, dist = self.create_dist()
         cmd = install_lib(dist)
@@ -89,8 +82,6 @@
         # get_input should return 2 elements
         self.assertEqual(len(cmd.get_inputs()), 2)
 
-    @unittest.skipUnless(bytecode_support,
-                         'sys.dont_write_bytecode not supported')
     def test_dont_write_bytecode(self):
         # makes sure byte_compile is not used
         pkg_dir, dist = self.create_dist()
diff --git a/Lib/packaging/tests/test_mixin2to3.py b/Lib/packaging/tests/test_mixin2to3.py
index 926f754..14a7487 100644
--- a/Lib/packaging/tests/test_mixin2to3.py
+++ b/Lib/packaging/tests/test_mixin2to3.py
@@ -9,7 +9,6 @@
                         support.LoggingCatcher,
                         unittest.TestCase):
 
-    @unittest.skipIf(sys.version < '2.6', 'requires Python 2.6 or higher')
     def test_convert_code_only(self):
         # used to check if code gets converted properly.
         code = "print 'test'"
@@ -26,7 +25,6 @@
 
         self.assertEqual(expected, converted)
 
-    @unittest.skipIf(sys.version < '2.6', 'requires Python 2.6 or higher')
     def test_doctests_only(self):
         # used to check if doctests gets converted properly.
         doctest = textwrap.dedent('''\
@@ -57,7 +55,6 @@
 
         self.assertEqual(expected, converted)
 
-    @unittest.skipIf(sys.version < '2.6', 'requires Python 2.6 or higher')
     def test_additional_fixers(self):
         # used to check if use_2to3_fixers works
         code = 'type(x) is not T'
diff --git a/Lib/packaging/tests/test_util.py b/Lib/packaging/tests/test_util.py
index c3d91aa..2872458 100644
--- a/Lib/packaging/tests/test_util.py
+++ b/Lib/packaging/tests/test_util.py
@@ -319,8 +319,6 @@
         res = get_compiler_versions()
         self.assertEqual(res[2], None)
 
-    @unittest.skipUnless(hasattr(sys, 'dont_write_bytecode'),
-                         'sys.dont_write_bytecode not supported')
     def test_dont_write_bytecode(self):
         # makes sure byte_compile raise a PackagingError
         # if sys.dont_write_bytecode is True
@@ -407,7 +405,6 @@
         finally:
             sys.path.remove(tmp_dir)
 
-    @unittest.skipIf(sys.version < '2.6', 'requires Python 2.6 or higher')
     def test_run_2to3_on_code(self):
         content = "print 'test'"
         converted_content = "print('test')"
@@ -422,7 +419,6 @@
         file_handle.close()
         self.assertEqual(new_content, converted_content)
 
-    @unittest.skipIf(sys.version < '2.6', 'requires Python 2.6 or higher')
     def test_run_2to3_on_doctests(self):
         # to check if text files containing doctests only get converted.
         content = ">>> print 'test'\ntest\n"