Minor and trivial, warning removal.

Better options handling and CLI help.
daemons/mrpd/ (mrpctl): minor, remove dummy code.
Some warning removal for:
warning: conversion to 'size_t' from 'int' may change the sign of the result [-Wsign-conversion]
warning: no previous prototype [-Wmissing-prototypes]
warning: format '%s' expects a matching 'char *' argument [-Wformat=]
warning: no previous prototype [-Wmissing-prototypes]
warning: unused variable [-Wunused-variable]
warning: switch missing default case [-Wswitch-default]