Fix another failing assertion with MSVC's STL in debug mode

Try to avoid derefencing an empty vector, even when the result is not used.

Change-Id: I8a8d8363f42dc3cea8ee702dc8555494b67a165d
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Fix a whole bunch of time conversion test failures on Windows

Take the daylight bias into account if GetTimeZoneInformation reports that the system is in a dayligh savings aware time zone

Change-Id: I4af7d284aa9147651c246b873c6f9d613b414832
Reviewed-by: Lars Knoll <lars.knoll@digia.com>