LU-7501 utils: clean up lfs argument handling/docs

Change "mdt-hash" option in lfs_setstripe() and lfs_setdirstripe
to use C99 formatting as used for other options.

Add comments for already-used options to lfs_find(), lfs_getstripe(),
and lfs_setstripe() to avoid conflicts in the future.

A few initializers can fit onto the same line with minor formatting
changes, better to be more compact than a slave to exact formatting.

Remove options that are obsoleted by LUSTRE_VERSION_CODE after 2.10.
Remove over-zealous deprecation of "lfs mkdir -c".

Sort options to be in mostly alphabetical order, unless the long
option parsing would return a deprecated short option.

Add deprecation warnings for short/long options that were deprecated
already in commit cdeb2f3a (http://review.whamcloud.com/22581

).

Fix up lfs-setdirstripe.1 and lfs-getdirstripe.1 man pages to list
preferred option names.  Also, lfs-getdirstripe.1 listed some options
that never existed, and others that were named incorrectly.

Move test scripts over to use preferred command and option names.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I74a59ce372115ae0906d0feb37c539a450bed6bd
Reviewed-on: https://review.whamcloud.com/28592


Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>