* afs.acl.ACL.retrieve(), equivalent to fs listacl
* afs.acl.getCallerAccess(), equivalent to fs getcalleraccess
Permissions are bitmasked, which can be masked against afs.acl.READ,
afs.acl.WRITE, etc. Implementation is based off of Perl AFS module,
although there are some notable differences in API.
Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>