File AUTHORS from the latest check-in

Primary Authors:
  * Roy Keene <libconfig@rkeene.org>
    Primary maintainer.

People who have submitted patches:
  * Jay Freeman
    strsep() implementation
  * Mirko Buffoni <mirko.buffoni @AT@ synthesys.it>
    Fixed installation issues and corrected mistakes in RPM spec file.
  * T. Hayfield
    Fixed issue with lc_process_var_double() handling the wrong type