Guru is not a thing any more.

Don't convert nulls to strings.

Update dependencies for pywinrm

This change is similar to https://github.com/ansible/ansible/pull/10465

It extends the logic there to also support none types.  Right now if you have
a '!!null' in yaml, and that var gets passed around, it will get converted to
a string.

eg. defaults/main.yml
```
ENABLE_AWESOME_FEATURE: !!null # Yaml Null
OTHER_CONFIG:
  secret1: "so_secret"
  secret2: "even_more_secret"

CONFIG:
  hostname: "some_hostname"
  features:
    awesame_feature: "{{ ENABLE_AWESOME_FEATURE}}"
  secrets: "{{ OTHER_CONFIG }}"
```

If you output `CONFIG` to json or yaml, the feature flag would get represented in the output
as a string instead of as a null, but secrets would get represented as a dictionary.  This is
a mis-match in behaviour where some "types" are retained and others are not.  This change
should fix the issue.

I also updated the template test to test for this and made the changes to v2.

Added a changelog entry specifically for the change from empty string to null as the default.

Made the null representation configurable.

It still defaults to the python NoneType but can be overriden to be an emptystring by updating
the DEFAULT_NULL_REPRESENTATION config.

cloudstack: fixes and consistency change

Make get_group run in O(n*log(n)) instead of O(n^2) by using a cache (#9437 rebase)

changed local_action to alias to connection=local vs delegate_to=locahost

double the speed of loading a 10k host inventory file (#10034 rebase)

first off, we add an oddly slow basic test of 10k item inventory

Before:
```
Ran 229 tests in 13.214s

OK

real    0m13.403s
user    0m12.106s
sys 0m1.155s
```

After:
```
Ran 230 tests in 21.328s

OK

real    0m21.516s
user    0m20.099s
sys 0m1.275s
```

since that seems like a bit long for the test to add to runtime, lets profile

`python -m cProfile -s time ./bin/ansible all -i test/units/inventory_test_data/huge_range --list-hosts`

Before:
```
         1272607 function calls (1259689 primitive calls) in 8.497 seconds

   Ordered by: internal time

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
    10000    4.393    0.000    4.396    0.000 __init__.py:395(_get_host)
    20000    2.695    0.000    2.697    0.000 __init__.py:341(__append_host_to_results)
    40369    0.113    0.000    0.113    0.000 {posix.lstat}
    50006    0.102    0.000    0.153    0.000 __init__.py:1490(combine_vars)
    40008    0.089    0.000    0.202    0.000 __init__.py:1546(_load_vars_from_path)
    20195    0.088    0.000    0.088    0.000 {posix.stat}
    10011    0.087    0.000    0.087    0.000 {posix.getcwd}
```

The top two lines are promising optimization targets

- populate Inventory's host cache more in _get_host, as we are looping
  over all the groups anyways.

- eliminate duplicate check of whether we've already included a host
  in the construction around __append_host_to_results we can infer
  presence of a host in the results list implies the presence of its
  name in the hostnames set, allowing us to only to the less expensive
  of the two checks

After:
```
         1252610 function calls (1239692 primitive calls) in 1.320 seconds

   Ordered by: internal time

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
    40369    0.105    0.000    0.105    0.000 {posix.lstat}
    50006    0.094    0.000    0.141    0.000 __init__.py:1490(combine_vars)
    40008    0.081    0.000    0.184    0.000 __init__.py:1546(_load_vars_from_path)
    10011    0.080    0.000    0.080    0.000 {posix.getcwd}
    20195    0.074    0.000    0.074    0.000 {posix.stat}
    10002    0.069    0.000    0.261    0.000 __init__.py:1517(load_vars)
```

fixes #11998, but still leaves issue of delegate_to: localhost not working

Updates to Windows Azure inventory from Tower.  

changed check to avoid OS X broken sem_getvalue()

fixes #11988

fixes #11907

refactored the options a bit, new inventory_opts made sense to always group
fixes #7917

fixes #11979

Add become support for OpenBSD doas

fixes #11982

* Speed up serialization of hostvars by simply using the internal
  dictionary used for cached lookups
* Use blocking gets/puts on queues instead of spin locking
* Merge sequential implicitly created blocks

cloudstack: add more common returns

Fix variable name mis-match in website docs for ANSIBLE_LIBRARY.