Also does some reorganization/cleanup on the magic vars/delegated
variable generation portions of VariableManager to make the above
possible.

Fixes #12633

Galaxy

better error reporting on fetching errors
use scm if it exists over src
unified functions in requirements
simplified logic
added verbose to tests
cleanup code refs, unused options and dead code
moved get_opt to base class
fixes #11920
fixes #12612
fixes #10454

Fixes #12605

This is because we pass the whole dd command string into the shell
that's running on the contained environment rather than running it
directly from python via subprocess without a shell.

Add explicit substitution of relative paths on the remote host just in case the connection programs do something unexpected.

Fixes #12621

Fix url lookup plugin HTTPError message not being reachable

Since Connection.execute_command() returns bytes, deal with the repurcussions

corrected output from default callback
added new tests for no_log loops
updated makefile test to check for both positive and negative occurrences of no_log

It's just s/extra_args/common_args/, but I reworded some parts to make
things a bit clearer too.

Closes #12335

The earlier code behaved exactly as though this default had been set,
but it was actually handled as a(n unnecessary) special case inside the
connection plugin, rather than set as an explicit default.

If the default is overriden either in ansible.cfg or the environment,
the new code will continue to work (in fact, it won't know or care,
since it just uses the value set in the PlayContext).

This is submitted as a separate commit for easier review to address
backwards-compatibility concerns.

Using set_host_overrides() in the connection plugin to access the ssh
argument variables from the inventory didn't see group_vars/host_vars
settings, as noted earlier. Instead, we can set the correct values in
the PlayContext, which has access to all command-line options, task
settings, and variables.

The only downside of doing so is that the source of the settings is no
longer available in ssh.py, and therefore can't be logged. But the code
is simpler, and it actually works.

This change was suggested by @jimi-c in response to the FIXME in the
earlier commit.

Now we have the following ways to set additional arguments:

1. [ssh_connection]ssh_args in ansible.cfg: global setting, prepended to
   every command line for ssh/scp/sftp. Overrides default ControlPersist
   settings.
2. ansible_ssh_common_args inventory variable. Appended to every command
   line for ssh/scp/sftp. Used in addition to ssh_args, if set above, or
   the default settings.
3. ansible_{sftp,scp,ssh}_extra_args inventory variables. Appended to
   every command line for the relevant binary only. Used in addition to
   #1 and #2, if set above, or the default settings.
3. Using the --ssh-common-args or --{sftp,scp,ssh}-extra-args command
   line options (which are overriden by #2 and #3 above).

This preserves backwards compatibility (for ssh_args in ansible.cfg),
but also permits global settings (e.g. ProxyCommand via _common_args) or
ssh-specific options (e.g. -R via ssh_extra_args).

Fixes #12576

should be last commit that fixes #12214

normalized outputs to use display class
cleaned up unused imports