[phobos] unittest failures for std.file and std.datetime

[Jonathan M Davis]

> Dunno which is at fault, but I erratically get the following on Windows:
> 
> core.exception.AssertError at std.file(779): unittest failure
> ----------------
> 615138
> 614FAF
> 5952ED
> 6098E6

It's trying to verify that the times from the file are correct - such as the 
time that the file was created. Unfortunately, it can't verify it exactly and 
so it has a bit of leeway in its check - 2 seconds. Apparently, on your 
machine, that leeway is too small. I believe that you increased the leeway on 
the Posix version of the test to 4 seconds just the other day because the 
leeway wasn't enough on your machine. It's the exact same problem here, only 
it's on Windows. Ideally, the tests would be exact, but they can't be, and 2 
seconds was generally working. Apparently, it's still not enough however.

- Jonathan M Davis