Fixes to archiver
Fixes to archiver

- localise variables
- use meaningful names
- don't reuse names unnecessarily
- use os.path.join to create paths; build up in stages
- comment fixes
- use LF not CRLF in writes to stderr
- include list-post in stderr

sebbASF/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,apache/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,sebbASF/infrastructure-puppet,sebbASF/infrastructure-puppet,apache/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet,apache/infrastructure-puppet,sebbASF/infrastructure-puppet