Removal or replacement of X-Pack icons

[lcawl]

Background

Currently, pages that contain X-Pack-specific information are identified as follows:

For non-floating chapters or sections like this, the source file contains:

[role=”xpack”]
[[section-name]]
=== Title

Likewise, floating sections within a page that are X-Pack-specific are tagged as follows:

[float]
[[section-name]]
=== [xpack]#Title#

The elastic/docs/resources/web/styles.css file contains details about how this role information is processed. A base64 encoded image is embedded in the CSS. For more information, see #177

Now that X-Pack is included as part of the default installation (per https://www.elastic.co/products/x-pack/open), the usefulness of those icons need to be revisited.

[lcawl]

The icon was updated to link to https://www.elastic.co/subscriptions
via #744