ber of an ar archive.

    Implements most of a file object interface: read, readline, next,
    readlines, seek, tell, close.

    ArMember objects have the following (read-only) properties:
        - name      member name in an ar archive
        - mtime     modification time
        - owner     owner user
        - group     owner group
        - fmode     file permissions
        - size      size in bytes
        - fname     file namec