Merge PR #268 - add daylight savings time toggle

Merge PR #268 - add daylight savings time toggle

Adds a toggle in the preferences face that allows the user
to enable or disable the daylight savings time.

Should help produce the correct results with the sunrise/sunset presets.

A proper solution would be to integrate the tzinfo database
but it's too big for the watch at the time of this writing.
Can't be done unless it can be shrunk down into a subset
the user would be interested. Even then it's a stopgap
since the database is likely to keep growing over time.

Reviewed-by: Matheus Afonso Martins Moreira <matheus@matheusmoreira.com>
GitHub-Pull-Request: https://github.com/joeycastillo/Sensor-Watch/pull/268