This command deletes a group, as `groupDelete` does, but works
for owners so that they can delete their own group.
`groupDelete` remains as a restricted command, able to delete any group.
Closes#40.
The commands selfListAccesses, accountListAccesses,
groupList, groupListServers, groupListGuestAccesses and
accountList now have options to filter their output through
pattern matching, with --include and --exclude.
The output from the commands using print_acls() is also more
human-friendly, with auto-adjusting column length, and empty
columns omitted.
Closes#60.
