- Reverted the change to round nanoseconds up or down in various
situtations. Now we always round down. This avoids the case where rounding
up would require us to then increment the second value (which could then
require us to increment the minute, which could then require us to increment
the hour, which could then ...).
In other words, we don't want to round 2011-12-31T23:59:59.999999 up to
2012-01-01T00:00:00, because that would be insane.
This applies to the return values for ->microsecond, ->millisecond, and the
%N specifier for strftime.
Patch by Martin Hasch. RT #79845.