No need for usage()
There are 2 arguments why -v and -h are broken:
1) if you are running off git, -v will show the last stable
release, effectively making this option useless.
people running stable versions leave open an attack surface
this way in case there are vulnerabilities found.
99% of the people are also using package managers to keep
their software up to date, instead of running $TOOL -v to
check how old it is.
2) -h is a sad excuse for not just looking at the manual page
(man 1 slock). Given we accept a post_lock_command, we can't
be as liberal and just intercept certain flags.
I changed the manpage to reflect this change.