ref #4518

This is what upstream musl does.

This is to avoid the message:
ERROR: You tried to add a non-repository package to system, but it would
 be lost on next reboot. Enable package caching (apk cache --help) or use
 --force if you know what you are doing.

By default we copy the tzdata file to /etc/zoneinfo and symlink to our
copy. We also purge all previously copied timezones unless -k is given.

If -i is specified, then will the tzdata apk package stay and the
symlink will point to /usr/share/zoneinfo/... instead of a copy in
/etc/zoneinfo/

musl uses /etc/zoneinfo/localtime

ref #927
fixes #2867

This is unix...

 - Removed obsolete modifier
 - Fixed typo

- ask for timezone after root password (before we start syslog)
- rephrase the questinos and fix input prompt to be on same line

initial cut at a setup-timezone script