on allocation failure instead of displaying a warning and deferencing NULL
pointer after. Spelling. Add prototypes. Add list of option in synopsis section
of man page, -d is not referenced because available as a compile option. It
should be made a runtime option btw.
without possibly losing lots of precision, and print the scale using
%g instead of %d in case it is non-integral. %g might not be the best
format for this.
