Depending upon the load order of rules, the output from ip[6]tables-save
will vary, as ip[6]_tables_names is sorted LIFO.  As reported by
Linus van Geuns, this makes comparing output from ip[6]tables-save across
reboots difficult.  Fix this by sorting table names prior to walking
the tables, making output consistent.

This closes bugzilla #580.

Phil

Signed-off-by: Phil Oester <kernel@linuxace.com>