Unfuck Locale on ios.

Turns out the java locale is pretty reliable on iOS.
Use monotouch time zone, not java.

Use of java time zone just crashes. This is probably screwed in puzzle pirates as well.

Also switched over to DateTimeOffset instead of DateTime. The former is simpler and less buggy.
DateTime is deprecated.
Added LocalTime and a conversion method.

This will allow many time calculations to be done platform independently, as long as the local time
zone is the only one needed.
Get rid of midnight method.

This can now be done using toLocal and reliable non-time-zone-specific manipluations.