When loading information from Mercurial commits, we assume that server

timezone is set to UTC. If it's anything else, the commit will be

converted to the wrong time. This was due to the usage of

datetime.fromtimestamp, which was converting into the local timezone.

We now use datetime.utcfromtimestamp to explicitly convert to UTC.
A unit test was added to test this situation.

Tested the original issue with a non-UTC timezone set, and saw the

failures in an existing commit. Also tested that the new unit test also

fails.
Verified after the commit that all unit tests pass, no matter my

configured timezone.