my extensions to TZ data

[Alois Treindl]

Currently I use these extensions to TZ database.

The files tzhist_world.txt tzhist_usa.txt tzhist_canada.txt can be compiled into binary TZ files
with the standard zic compiler contained in the tzcode package.

The shell script mk_zones.public does that together with all the official TZ zones.

#!/bin/bash
# compile zones including local zones maintained by Alois Treindl
PZONES="tzhist_world.txt tzhist_usa.txt tzhist_canada.txt "
touch backzone africa antarctica asia australasia europe northamerica southamerica $PZONES
PACKRATDATA="backzone $PZONES"
echo $PACKRATDATA
export CC='gcc -std=gnu11'
make  PACKRATDATA="$PACKRATDATA" zones
make zdump