Shinmera/file-attributes

Access to common file attributes (uid, gid, permissions, ctime, mtime, atime)

## About File-Attributes
This is a small OS portability library to retrieve and set file attributes not supported by the Lisp standard functions.

## How To
Simply use the functions ``access-time``, ``modification-time``, and ``creation-time`` to access the relevant timestamps. Some stamps may not be accessible or modifiable depending on your OS or file system.

In order to manage attribute information, use ``owner``, ``group``, and ``attributes``. The values used are OS specific for these functions, though the attributes flag can be decoded and encoded via a standardised form with ``decode-attributes`` and ``encode-attributes``.

Any of the above operations may signal an error if the file does not exist, is inaccessible, the operation is not possible, or some other failure occurred.