Provides some commands and functions to pack and unpack
archives in a simple way.

Commands to pack/unpack archive files can be defined by setting `pack-program-alist'
variable.

Use from Dired
--------------

To pack/unpack files from dired buffers, add following to your dired confiugration:

(define-key dired-mode-map "P" 'pack-dired-dwim))

This command creates an archive file from marked files, or unpack the file when
only one file is selected and that has an extension for archive.