std.datetime, destructors, and dustmite

[Walter Bright via Digitalmars-d]

In order to make D viable for refcounting, I have to fix all the issues with 
destructors. Some problems with destructors have shown up with std.datetime, but 
getting a reduced example from that tangle is difficult.

If anyone wants to lend a hand and dustmite them down to canonical examples, it 
would be most helpful.

The relevant bug reports are:

https://issues.dlang.org/show_bug.cgi?id=13719
https://issues.dlang.org/show_bug.cgi?id=13720
https://issues.dlang.org/show_bug.cgi?id=13721

Thanks for any help!