2.7.91 released May 14, 2000

- all functions in sgffile.c are now prefixed with sgffile_ instead of
  sgf_ to separate them from functions which handle SGF trees
- some minor cleanup in dragon.c
- globals last_move_i, last_move_j made local to interface/play_ascii.c
- functions save_state() and restore_state() removed together with
  variables white_captured_backup and black_captured_backup.
- move reasons are now sorted
- inclusion of sys/time.h made contingent on HAVE_SYS_TIME_H in utils.c
- inclusion of time.h and/or sys/time.h removed from hash.c and
  interface/play_solo.c
- one new pattern in eyes.db