Ansible vault: a framework for encrypting any playbook or var file.

Fixes #6056

Update intro_installation.rst

Copy action_plugin: encode content when dict.

When content is processed and found to be valid JSON it is decoded into a dict. To write it out to a file we need to encode it back into a string.

Addresses GH-5914.

docs_pull_request: Add parameters highlighting

Set use_mirrors default to "no" for the pip module

Fix zfs create command for properties with spaces

Update guide_aws.rst

Signed-off-by: Brian Coca <briancoca+dev@gmail.com>

PyPI moved to a CDN on 2013-05-26, so mirrors are now largely
unnecessary and pip removed the functionality in 1.5. More importantly
(and why I wrote this request): on 2014-02-15 the mirror directory was
taken offline, so mirrors may not work anymore even for pip versions
that support them.

Docsite: Fixed typo.