minor, provide info page for tzmaps

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, actually provide iata.tzmap and icao.tzmap

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, announce d/l links for supported .tzmaps

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>