* use xz when lzma is called for, and stop suggesting both lzma since it's
no longer used, and xz-utils since it's now priority required,
closes: #582706, #523494
* use xz when lzma is called for, and stop suggesting both lzma since it's
no longer used, and xz-utils since it's now priority required,
closes: #582706, #523494