Rework of archiver
Rework of archiver

Common approach for working with archives is introduced.
Unpacker and Archiver interfaces are added.

Example of file unpacking:
 archive, _ := debos.NewArchive("file.ext")
 archive.Unpack("destination")

Three archive types are supported:
- tar
- zip
- debian packages

Type of archive is guessed by extension or can be set explicitly during
archiver creation with option for NewArchive().

Signed-off-by: Denis Pynkin <3fbf95ee68899518ee8799d35f88c8f7982aa936@collabora.com>

go-debos/debos,d4s/debos