Introduce assertions for DateTime

[luebbe]

As always, a PR out of personal need :)

Since Assert.AreEqual can't really distinguish between date/time values and floats and Assert.IsTrue(SameDate(...)) doesn't really help to point out the differences, I introduced assertions for date/time values.

DUnitX' own tests deliver failing tests on German locale, because TValue.From fails to parse the English dates in the test cases (All dates convert to 30.12.1899). This is why I can show you some nice before/after screenshots here.

Before (using Assert.IsTrue):

After (using the new assertions):

You can provoke failures on Englisch locale if you set expectedDate and expectedTime in DUnitX.Test.Utils to something else.

90% of the changes in Tests/DUnitX.Tests.Utils.pas are caused by tabs being converted to spaces when the file was saved.

Maybe we need an IFDEF for XE* Versions. I don't know when the Same(Date/Time) functions where introduced. The new assertions should at least work from Delphi 10 onwards.

[vincentparrett]

Thanks, this looks good - I wasn't able to check D2010 & XE as I don't have them installed, but SameDate appears in XE2 (the earliest version I have installed). Not too worried, we can IFDEF for XE or earlier for now until we know for sure.

[vincentparrett]

Hi Luebbe

Can you merge master into your branch and fix the conflicts and I will merge the PR. We can deal with 2010/XE if someone has a problem. Gemini tells me SameDate was added in D6 but who knows if that is correct.