Revert "No longer need to reference 'version_added' in docs for these, as this was quite a while ago."

This reverts commit ff0a41d4.

Fixes #4677
Fixes #4657
Fixes #4599

script there with a comma that would produce invalid configuration
upon being wrote again

it start to duplicate line, because this create
a empty option in the list, and so the module add a new line along the previous
one. See

>>> ' a,b, '.strip().split(',')
['a', 'b', '']

If a specified key did not have a comment, it would be ignored as
an invalid key.

Fixes #4513

According to the sshd man page, no spaces are permitted between the
options of an authorized ssh key

This allows to remove a key without knowing the options in the
authorized_key file

A small refactoring of the authorized_key module to accomodate these
changes, plus fixing some things like not rewriting the file on every
new key. These changes bring the original feature for ssh options in-
line with the comments in #3798

Fixes #3785

  Migrated all examples: in DOCUMENTATION=''' string to standalone EXAMPLES=''' string
  Added deprecation warning to moduledev.rst and remove deprecated example from it
  Fixed up a few typos and uppercased some acronyms.
  add consistency to how EXAMPLES are formatted

* Clarified the meaning of 'user'
* Changed 'sshdir' to 'path' in the example
  * 'sshdir' is used internally in the module, but the argument is 'path'
* Made the capitalization consistent in the descriptions

This commit fixes a bug where the authorized_key module causes
the ~user/.ssh directory to be owned by root instead of the user,
when the manage_dir argument is not specified.

If the manage_dir argument was not specified, the module behaved as if
manage_dir was set to false, even though it's supposed to default to
true.

This module assumed that an optional argument, with no default
specified, will not be present in the module.params dictionary.

What actually seems to happen is that the argument does appear in
the module.params dictionary with a value of None.

The upside is that this line was evaluating to None instead of
true:

    manage_dir = params.get("manage_dir", True)

I fixed the problem in this particular module by explicitly specifying
the default value for the manage_dir arugment. But if this bug
occurred because of a change in behavior in AnsibleModule, then other
modules may be broken as well.

step
Signed-off-by: Brian Coca <briancoca+dev@gmail.com>

Showcase the new-style lookup plugin access in the authorized_key docs rather than the old-style $FILE

Showcase the new-style lookup plugin access in the authorized_key docs rather than the old-style $FILE

Three changes:
* Add set_default_selinux_context() to module_common that sets
  a file's context according to the defaults in the policy
* In atomic_replace(), set the default context for the file if
  selinux is enabled and the destination file does not exist.
* In authorized_key, set the default context when creating
  $HOME/.ssh and $HOME/.ssh/authorized_keys.  If these already
  exist, this won't touch them.