Use rich comparisons for Attribute and FieldAttribute

Fixes #12206

  ansible is passing unicode arond internally so we should test the same
  data.
* Add a zero length test for _count_newlines and fix the zero newlines
  test to have no newlines.

Fix for one half of hte bug reported in #12198

Because __cmp__ is not supported on Python 3.

Remove duplicated function definition (fallout from earlier repeated merge)

dbd755e0 previously assigned the value to self._templar.environment.searchpath,
which is incorrect - it needs to be assigned to the environment.loader.searchpath
value instead.

Fixes #11931

Fixes #12180

* Dedupe combine_vars() code (removed from VariableManager)
* Fix merge_hash algorithm to preserve the type
* unittest combine_vars and merge_hash

Adds utf-8 encoding to f5 module_utils

Show module name and args with -vvv

This information was earlier shown only with ANSIBLE_DEBUG, but it's
extremely useful in a user context, especially with module invocations
with deeply nested args like the ec2_vpc/ec2 modules.

Closes #11680

Fixes #12155

Changelog tweak: Mention --output - for ansible-vault encrypt/decrypt

Fix setting dns_name in cobbler inventory

Fixes #12081

Add Nagios NDO inventory plugin

The contributor's name on line 10 (originally line 7) includes a character
that the default Python encoding (ASCII) raises an error on when interpreting
the file.

Specifying the utf-8 encoding, as is done in other modules, resolves
the error.

The error being raised is

SyntaxError: Non-ASCII character '\xc3' in file /.../lib/ansible/module_utils/f5.py
on line 7, but no encoding declared; see http://www.python.org/peps/pep-0263.html
for details

Fixes #12154

Make combine_vars() compatible with Python 3