Invalidate host/group variables cache when loading

extra varsiables based on playbook basedir.
Merge branch 'sergevanginderachter-vars4pb_basedir' into devel
Merge pull request #7477 from sivel/rax-user-data

rax module: Support config_drive and user_data
Merge pull request #7478 from sivel/rax-keypair-filepath

rax_keypair module: Allow public_key to be a path to a file
Fix the name of the package that provides apt-add-repository on Ubuntu
Merge pull request #7650 from sivel/guide-rax-automation

Rax Guide: Add RackConnect and Managed Cloud automation check examples
Merge pull request #7649 from sivel/vault-password-script

Allow --vault-password-file to work with a script as well as a flat file
Merge pull request #7605 from sivel/delegate-callback-hint

Show delegate_to hint in callback output
CHANGELOG updates for new features
Added setting of the health_check options on an existing ASG
Merge branch 'rax-ptr' of https://github.com/sivel/ansible into sivel-rax-ptr
Adding a note about 'type' field becoming required in rax_dns_record
Merge branch 'sivel-rax-ptr' into devel
Update lineinfile
Merge branch 'wait-for-port-search-regex' of https://github.com/sivel/ansible into sivel-wait-for-port-search-regex
New option for route53: retry_interval

The current (hard-coded) retry interval of 500 seconds can cause ansible to have excessive run-times in the case of many domains. `retry_interval` provides a way to customize the wait between retries of calls to route53.
Break out of loop for sockets in wait_for when there's no data to read
Merge branch 'sivel-wait-for-port-search-regex' into devel
Merge branch 'task-host-loop-bypass' of https://github.com/sivel/ansible into sivel-task-host-loop-bypass
Adding run_once feature to CHANGELOG