Revert 17c5ee87

This change effectively reverts 17c5ee87, but leaves in some additional
comments added by that commit.

As to why this change is no longer needed, the assumption that needing
a separate cloud files tenant ID to form your glance swift user name
was incorrect.  Using the format of <cloud_tenant_id:cloud_username>
works fine.

Addresses issue #281

(cherry picked from commit ca13acfde88f522f0e10f78cd333214860f20e29)