feat(bkgpslog): Append to daily tar

* Set version to 0.1.0.

* Rewrote write loop to append location data to tar file instead of
writing each file written by each buffer round directly to
disk. Tar contains individually encrypted and compressed files; no
attempt at merging location data between buffer rounds was attempted.

* Add functions:

- setTimeZoneEV (exports TZ)
- dateShort (returns current date in `YYYYmmdd` format via stdout)
- timeDuration (given seconds, returns ISO-8601 period; Ex: PT60S)
- displayMissing (displays missing apps, files, and dirs)
- setScriptTTL (sets script TTL given "day" or "hour")

* Set default script TTL to "day" (was "hour")

* Set default TZ to UTC. Added option `--time-zone`.