Basic groundwork for s3 module.

Re-worked this module by removing some complexity and added a list of to-do features.  In a previous pull request, the commit had additional parameters which in my mind made it confusing since this module is supposed to be idempotent.  I'll revisit a dedicated download/fetch option in the near future. 

Hoping that in this form it will get some interest from folks who want to hack on it to add desired features.