2.7.49 released March 15, 2000

- bugfix in make_dragons (--mouse could cause crash)
- bugfix in mouse_determine_life
- bugfix in vgprintf
- new function vital_chain
- new autohelper functions singleton and vital_chain
- mouse tuning
- new eye pattern
- mouse code documented
- string.h included in incremental_board.c to stop warning
- sgf functions cleaned up by passing around a file handle instead of
  sharing a global one
- minor optimizations in break_chain() and relative_break_chain()
- minor changes and more comments in incremental_board.c
- stack implementation revised in incremental_board.h