Ansible 2.3 feature support for dellos6. (#23084)

* Ansible 2.3 feature support for dellos6.

- With the new Ansible 2.3 infra changes, the dellos modules doesn't work
  (the new infra changes are not backward compatible), so added the below
  changes support it.
- Added the new terminal plugin for DellOS6
- Added the new action plugin for DellOS6
- Modified the modules to work with the new infra.
- with that it adds support for DellOS6 Persistent Connection support.

* Remove pep8 confirming files from dellos6.py and dellos6_config legacy-files

lib/ansible/plugins/terminal/dellos6.py

@@ -0,0 +1,73 @@
+#  2016 Red Hat Inc.
+#
+# 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/>.
+#
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import re
+import json
+
+from ansible.plugins.terminal import TerminalBase
+from ansible.errors import AnsibleConnectionFailure
+
+
+class TerminalModule(TerminalBase):
+
+    terminal_stdout_re = [
+        re.compile(r"[\r\n]?[\w+\-\.:\/\[\]]+(?:\([^\)]+\)){,3}(?:>|#) ?$"),
+        re.compile(r"\[\w+\@[\w\-\.]+(?: [^\]])\] ?[>#\$] ?$")
+    ]
+
+    terminal_stderr_re = [
+        re.compile(r"% ?Error: (?:(?!\bdoes not exist\b)(?!\balready exists\b)(?!\bHost not found\b)(?!\bnot active\b).)*$"),
+        re.compile(r"% ?Bad secret"),
+        re.compile(r"invalid input", re.I),
+        re.compile(r"(?:incomplete|ambiguous) command", re.I),
+        re.compile(r"connection timed out", re.I),
+        re.compile(r"'[^']' +returned error code: ?\d+"),
+    ]
+
+    def on_authorize(self, passwd=None):
+        if self._get_prompt().endswith('#'):
+            return
+
+        cmd = {'command': 'enable'}
+        if passwd:
+            cmd['prompt'] = r"[\r\n]?password:$"
+            cmd['answer'] = passwd
+        try:
+            self._exec_cli_command(json.dumps(cmd))
+        except AnsibleConnectionFailure:
+            raise AnsibleConnectionFailure('unable to elevate privilege to enable mode')
+        # in dellos6 the terminal settings are accepted after the privilege mode
+        try:
+            self._exec_cli_command('terminal length 0')
+        except AnsibleConnectionFailure:
+            raise AnsibleConnectionFailure('unable to set terminal parameters')
+
+    def on_deauthorize(self):
+        prompt = self._get_prompt()
+        if prompt is None:
+            # if prompt is None most likely the terminal is hung up at a prompt
+            return
+
+        if prompt.strip().endswith(')#'):
+            self._exec_cli_command('end')
+            self._exec_cli_command('disable')
+
+        elif prompt.endswith('#'):
+            self._exec_cli_command('disable')