More descriptive names are now used in order to make tracebacks
more readable.

change).  configure will be regenerated in the next commit.

changes).

Patch by Roger Serwy.

Patch by Roger Serwy.

to a single #define instead of having several copies in several files.

This excludes the Modules/ tree (datetime and expat both have a copy
for their own purposes with no need for it to be the same).

This copy also had a bug in it, it fails to incorporate the length
into the hash by using it as the loop variable so it'll always be -1
by the time it is XORed in.

As such: I'm doing this only in Python 3.3 and not backporting as it
would change the existing hash behavior of datetime objects.