Fix UTC handling in DateTime parsing
Fix UTC handling in DateTime parsing

Fixes #713

The resulting DateTime must always be in UTC. Peachpie DateTime expects that and stores the timezone information separately. If DateTime.Time.Kind is left Unspecified, later timezone conversions (TimeZoneInfo.ConvertTime) might incorrectly assume the local time zone.

iolevel/peachpie-concept,iolevel/peachpie,iolevel/peachpie,peachpiecompiler/peachpie,peachpiecompiler/peachpie,iolevel/peachpie-concept,iolevel/peachpie-concept,iolevel/peachpie,peachpiecompiler/peachpie