Add an inode creation time field. It's created for all new inodes.
It's visible to stat_more. setattr_more can set it during
restore.
Signed-off-by: Zach Brown <zab@versity.com>
Make it static and then use it both for argp_parse as well as
cmd_register_argp.
Split commands into five groups, to help understanding of their
usefulness.
Mention that each command has its own help text, and that we are being
fancy to keep the user from having to give fs path.
Signed-off-by: Andy Grover <agrover@versity.com>