gdbm: implement gdbm-setopt
gdbm: implement gdbm-setopt

mcandre/factor,erg/factor,erg/factor,mcandre/factor,kingcons/factor,erg/factor,kingcons/factor,mcandre/factor,erg/factor,erg/factor,mcandre/factor,mcandre/factor,kingcons/factor,mcandre/factor,erg/factor,mcandre/factor,erg/factor,kingcons/factor