bug#13737: Add -h option to 'users'

[Paul Eggert]

On 02/18/2013 01:44 PM, anatoly techtonik wrote:
> "-h" is already a well matured practice to be
> implemented

'-h' means something other than "help" for 
many common GNU commands: ls, touch, sort, bash, etc.
If we got people into the habit
of thinking '-h' means help, they'll get confused
when "ls -h" doesn't do what they expect.  It may
be better to leave sleeping dogs lie.