POSIX ACLs for Python

File Release Notes and Changelog

Release Name: 0.3.0

Notes:
Under Linux, implement more functions from libacl:
  - add ACL(mode=...), implementing acl_from_mode
  - add ACL().to_any_text, implementing acl_to_any_text
  - add ACL comparison, using acl_cmp
  - add ACL().check, which is a more descriptive function than validate


Changes: