Feature: Optionally include archive table of contents

This is to address #8 (closed) by adding a new option --archive-toc. If this option is specified, we'll examine the table of contents from any archive that is being packaged up, and include those files in the inventory.

Any archive format supported by archive will get picked up here, regardless of filename/extension. Doing this examine will add a little latency, so it's off by default for now