Checking for sshpass is peripheral to the calling code, so it's easier
to follow when the details are moved into a method.

Clarify why we add -q only for ssh

Python 3: the StringIO module is gone

Fixes 17 failing tests on Python 3.4, restoring the 8 failures we had
last Friday.

Output proper JSON from vbox dynamic inventory contrib script

fix no self pointer out of class.

Also get pipelining working for people who look to chroot as an example
for their own connection plugins

Note: In the latest v2 API, action handles become but chroot doesn't
reliably handle become.  Maybe we need to add a has_become attribute
that the action can display an appropriate error.

This can happen in chroot environments that don't have all of /proc
available

Helps connection plugin implementors understand how to structure
exec_command()

Fixes #12526

Update outdated comment

Since #12165 was merged, hostnames are properly validated.

We now use "sudo -n" instead of "sudo -k && sudo …"

Clarified that .yml, .yaml, and .json are allowable file extensions for inventory vars files

Also strip UnsafeProxy off of low level srings and objects to ensure
they don't cause issues later down the road

Fixes #12513

Typo in shell command in example

Python 3: make test_variable_manager_precedence pass

Fixes #12501

Due to the way we're now calculating delegate_to, if that value is based
on a loop variable ('item') we need to calculate all of the possible
delegated_to variables for that loop.

Fixes #12499