Fix std.datetime autotester failure for FreeBSD 10.3/11.

[jmdavis]

The tests fail depending on your timezone due to a known FreeBSD bug, so
we need to disable them until the bug in FreeBSD gets fixed.

[JackStouffer]

Hmm, seems like this could be easily forgotten and left in.

Is there any way that this can be special cased for a specific version range of FreeBSD? So then it will automatically be run when a new FreeBSD version comes out? That way it's impossible for us to forget about this.

[jmdavis]

Is there any way that this can be special cased for a specific version range of FreeBSD?

Not AFAIK, and even if we could, it doesn't help any, because there isn't a FreeBSD version where it's been fixed, and all supported versions of FreeBSD have the bug. Also, we've already versioned out code elsewhere in std.datetime because of this bug, so this isn't new. It just wasn't hitting on the autotester previously, because it's been on FreeBSD 8 (which doesn't have the problem), and it doesn't fail for those of us running FreeBSD locally (at least not on the machine of anyone who's said anything), because we're not in a timezone where it happens to fail.

Regardless, since I run FreeBSD for my main machine, I don't think that it's going to be forgotten. The main issue is figuring out how to get the fix into FreeBSD, which I need to find the time to do.