Add run_once task key

This caused the task to act like  bypass host loop plugin and
execute only on a single host. Can be used with delegate_to
Allow public_key to be a path to a file
Add PTR record support to rax_dns_record
Add user_data and config_drive support
Switch functions over to kwargs to make it easier to manage in the future
Mention that user_data can be a file path or a string
Allow search_regex to be used in wait_for with port
Add rackconnect and managed cloud automation check examples
Allow --vault-password-file to work with a script as well as a flat file
Show delegate_to hint in callbacks
Adding a Collins inventory script for Ansible
Moving to_safe back into class for consistency purposes
Don't write to cache if queries fail
Merge pull request #8089 from ssalevan/ssalevan/add-collins-inventory

Adding a Collins inventory script for Ansible
Correcting var blending integration test
Added exception handling to database creation and deletion. Fixes #8075.
Switched primary and alias names of the name/db parameter, to match documentation. Fixes #8065.
Fixed tracebacks when datacenter not found, when notes not given, and when collecting facts after VM creation. Fixes #8067.
Documentation simplification for git module parameter
Merge pull request #8093 from ghjm/mysql-dbname

Switched primary and alias names of the name/db parameter. Fixes #8065.