tar: add utilities for folding over archive entries

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Update CHANGES

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Release 0.2

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Merge pull request #3 from djs55/detect-unix

tar: add utilities for folding over archive entries