Fix #1460 - conversion of win32 variant dates within DST offset windows

[eranl]

The main goal here is to fix #1460, which I found can be done in a straightforward way by using:

• java.util.Calendar for converting between UTC and local time, and
• win32 APIs for converting between local time and variant date.

While testing the fix, I realized that dates with non-zero millisecond values were not converted correctly by the win32 APIs, so I added some correction logic for preserving millisecond values. BTW, I found that the existing implementation didn't handle some millisecond values correctly either.

Overall, this is relatively simple logic, avoiding the reconstruction of complex calculations provided by the above APIs.

Added OleAuto.VariantTimeToSystemTime and a test for it.
Added tests for DST offset window that fails with existing logic, and tests for millisecond dates, some of which fail with existing logic.

Note: OaIdl.DATE_OFFSET is not used anymore, but I left it in since it's declared public.

[matthiasblaesing]

Change looks good to me. I would have preferred a pure-java way, but using the native function looks reasonable. Appveyor is also happy. Please:

• squash the two commits into one
• make sure valid author information is present

For the latter you can check the info using the call git log -n 1 or any git client, that is not github, which tries to be to clever. The author information should hold your real name and a valid e-mail.

https://www.git-tower.com/learn/git/faq/change-author-name-email
https://stackoverflow.com/questions/16217801/git-rebase-change-author
https://stackoverflow.com/questions/750172/how-do-i-change-the-author-and-committer-name-email-for-multiple-commits

[eranl]

Thanks for your feedback.

* squash the two commits into one

Done

* make sure valid author information is present

For the latter you can check the info using the call git log -n 1 or any git client, that is not github, which tries to be to clever. The author information should hold your real name and a valid e-mail.

https://www.git-tower.com/learn/git/faq/change-author-name-email
https://stackoverflow.com/questions/16217801/git-rebase-change-author
https://stackoverflow.com/questions/750172/how-do-i-change-the-author-and-committer-name-email-for-multiple-commits

I updated my real name. For email, I've followed these guidelines for private addresses.

[matthiasblaesing]

I updated my real name. For email, I've followed these guidelines for private addresses.

Please use a real e-mail adress for author information.

[matthiasblaesing]

@eranl any update on this?

[eranl]

I would like to avoid exposing my email address publicly. GitHub supports a way to identify authors and communicate with them while keeping their email addresses private, so I'd like to continue using that.

[matthiasblaesing]

Regrettably then someone else needs to redo the work. I will not merge without full author information.

[eranl]

Ok, I give up. Just updated my email address.