sysstat-12.1.6

sysstat-12.1.6

sysstat version 12.1.6 final packaging.
lsm and spec files updated.
Changelog added.

In this version, the iostat command has been heavily modified for better
performance. In particular devices structures are now dynamically allocated
to make sure you won't miss a device if many of them are added to the
system while iostat is running. Also sysstat test environment now
includes a large set of non regression tests for iostat.

Signed-off-by: Sebastien GODARD <sysstat@users.noreply.github.com>