New DateTimeType Test

Regarding of the always failing DateTimeType tests where I assumed the tests failed on all non CET time zone hosts.
So I took the time to write a new test which should be more fail safe to whatever time zone is on the build host.

I seems to be a bit exaggeratedly in compare with the old one, but why not, tests are never to much ;)
I tried to comment as much as possible, so hopefully others than me can read the code too.
To reproduce the test results better, I also drop some lines to the console which should be easy to read.

I tested in on different hosts with different time zones, but the test is written that this shouldn't care, because it sets the default time zone by itself for the test.

Let me know if I should change something or even if I should add remove test parameters.