Mark,

I am reassigning this to you for commit review.  I am changing the title to reflect the visible part of the change.  The datetime module gains direct access to system gettimeofday at the C level while time module grows time.gettimeofday() Python method.

I am not sure I made the best choice defining struct timeval on systems without gettimeofday.  Maybe it is better to do

typedef struct timeval _PyTime_timeval;

on systems with  gettimeofday and equivalent explicit definition on systems without.

The cast selection logic for time_t is a bit of a hack as well, but this is the best I could come up with without resorting to configure tests.  Unless this breaks on a known platform, I would rather commit this as is and have a separate project to clean up cross-platform time handling later.

This patch builds on refactoring started in issue9012.