Option to print out help

(currently lacking in actual help)
Change verbose output to a getopts option
Start migrating to a new pattern for using $arg
Document stats in help
Improve verbosity and document `scan`
Improve and document listing duplicates
Document listing individual file matches
Document and improve deleting files from directory
Document and improve rescanning
Document wiping data
Option to delete duplicates in other directories
Makefile to install duplicates in `~/bin`