Build failures due to Timestamp precision

[eleftherias]

Tests relying on HSQLDB 2.5.1 are failing because of https://sourceforge.net/p/hsqldb/bugs/1585/

We will temporarily change our assertions on Timestamp values to be more lenient (to the millisecond).

[eleftherias]

It appears this is still an issue on Windows.

[jzheaux]

I wonder if when the issue is fixed with Windows, this commit can also be reverted: a0a9718