Various python3 updates for module_utils: (#17345)

* Port set_*_if_different functions to python3
* Add surrogate_or_strict and surrogate_or_replace error handlers for
  to_text, to_bytes, to_native
* Set default error handler to surrogate_or_replace
* Make use of the new error handlers in the already ported code
* Move the unittests for module_utils._text as they aren't in basic.py
* Cleanup around SEQUENCETYPE.  On python2.6+ SEQUENCETYPE includes
  strings so make sure code omits those explicitly if necessary
* Allow arg_spec aliases to be other sequence types

test/units/module_utils/test_text.py

@@ -0,0 +1,65 @@
+# -*- coding: utf-8 -*-
+# (c) 2016 Toshio Kuratomi <tkuratomi@ansible.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division)
+__metaclass__ = type
+
+from ansible.compat.six import PY3
+from ansible.compat.tests import unittest
+from units.mock.generator import add_method
+
+
+# Internal API while this is still being developed.  Eventually move to
+# module_utils.text
+from ansible.module_utils._text import to_text, to_bytes, to_native
+
+# Format: byte representation, text representation, encoding of byte representation
+VALID_STRINGS = (
+        (b'abcde', u'abcde', 'ascii'),
+        (b'caf\xc3\xa9', u'caf\xe9', 'utf-8'),
+        (b'caf\xe9', u'caf\xe9', 'latin-1'),
+        # u'くらとみ'
+        (b'\xe3\x81\x8f\xe3\x82\x89\xe3\x81\xa8\xe3\x81\xbf', u'\u304f\u3089\u3068\u307f', 'utf-8'),
+        (b'\x82\xad\x82\xe7\x82\xc6\x82\xdd', u'\u304f\u3089\u3068\u307f', 'shift-jis'),
+        )
+
+def _check_to_text(self, in_string, encoding, expected):
+    """test happy path of decoding to text"""
+    self.assertEqual(to_text(in_string, encoding), expected)
+
+def _check_to_bytes(self, in_string, encoding, expected):
+    """test happy path of encoding to bytes"""
+    self.assertEqual(to_bytes(in_string, encoding), expected)
+
+def _check_to_native(self, in_string, encoding, py2_expected, py3_expected):
+    """test happy path of encoding to native strings"""
+    if PY3:
+        self.assertEqual(to_native(in_string, encoding), py3_expected)
+    else:
+        self.assertEqual(to_native(in_string, encoding), py2_expected)
+
+
+@add_method(_check_to_text, [(i[0], i[2], i[1]) for i in VALID_STRINGS])
+@add_method(_check_to_text, [(i[1], i[2], i[1]) for i in VALID_STRINGS])
+@add_method(_check_to_bytes, [(i[0], i[2], i[0]) for i in VALID_STRINGS])
+@add_method(_check_to_bytes, [(i[1], i[2], i[0]) for i in VALID_STRINGS])
+@add_method(_check_to_native, [(i[0], i[2], i[0], i[1]) for i in VALID_STRINGS])
+@add_method(_check_to_native, [(i[1], i[2], i[0], i[1]) for i in VALID_STRINGS])
+class TestModuleUtilsText(unittest.TestCase):
+    pass