Add a Statx wrapper for ceph_statx.
Add a type wrapping the statx status info that exposes the various
fields from the C-struct.
Add a type wrapping struct timespec, based on golang's x/sys, for the
time fields in the struct.
Note that the ceph struct is not the same as the linux statx struct.
Signed-off-by: John Mulligan <jmulligan@redhat.com>
