Message 99139 - Python tracker

Ok, will do the upload to rietveld.

In addition to the straight review of the patch itself, you could:
 - diff against the upstream source code (very few changes)
 - diff between 2.x and 3.x
 - review the test_suite (there's only additions, no real change)
 - hunt refleaks

Btw, I've backported the last tests (#2746, #6233) to all 4 test files (ET and cET, 2.x and 3.x).