Change ordering of HAVE_TM_ZONE and HAVE_INT_TIMEZONE code blocks

 to give HAVE_TM_ZONE priority. This fixes glibc2 machines and any other
 machine which passes both tests in configure.
Repair HAVE_TM_ZONE code which stuffs tm structure with date type values.
 Same problems as were originally there before v6.1, but never noticed.
Thanks to Oleg for nagging :)