Update playbooks_blocks.rst

Remove heading that appears to be extraneous.

Indicate that credstash plugin is new in v2

Also offer a poor-man's alternative.

Displays the absolute path of a given task when verbosity is above level 3

Show a nice error if the role name is missing.

Explictly set the version of strict mode to use for powershell modules.

Add an example for map() to the filters page.

Fixes #12654

Fixes #12602

Fix ansible-vault rekey

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.