Adds an unclean implementation of silent cron mode
Adds an unclean implementation of silent cron mode

* calls `log` instead of `printf` / `echo` each time an output should be
  omited if in silent/quiet mode
* quiet mode activates using -q / --quiet flag in cron mode

This is very rudimental as some (useful) output might be omited in
silent mode, my goal was an easy implementation to fit my personal needs

dennisschuerholz/dehydrated