unarchive module & action plugin

copies archive to host and unpacks it where you want

handles :
   - gzip,bzip2 and xz compressed tarfiles
  - uncompressed tar files
  - .zip files (does not detect changed/OK)

Detects archive type automatically
Detects if archive already unpacked for tar files, but not .zip files

Internally, uses a list of archive handler objects.  Selects handler by trying a list type operation (EG tar -t) with each one until one works.