Timestamp timezones are ignored

[johannish]

Commit a19b9e02 added basic support for Timestamp with timezone and Timestamp with local timezone, but still does not properly calculate the UTC time based on the timezone information.

I've made a quick attempt at handling the timezone, but I would like some feedback about this approach. It's necessary to know whether the Timestamp coming into OracleTimestampToV8Date(...) has timezone information because the call to d->getTimeZoneOffset(...) will always return something, even if the type was a Timestamp without timezone.

What do you think about the approach of handling all Timestamp types in a single function? raztus/node-oracle@95875370