[FYI] maint merged into yacc-work

[Stefano Lattarini]

The yacc-work branch, due to its slow advancing pace, was falling more 
and more out of sync with maint, and thus with all the improvements
and bug fixings done there in the meantime.  Since yacc-work is meant
to be eventually merged into either maint or master (we still have to
decide which one fits better), there is no point in leaving this
situation worsen further.  I've thus merged maint into yacc-work,
fixed the spurious resulting conflicts, and pushed.

Thanks,
  Stefano