gdbm: better option setters
gdbm: better option setters

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