Message 72129 - Python tracker

I have found out that the result of math.log(x, 10) is slightly more
inaccurate than the one of math.log10(x). Probably the best example is
math.log(1000, 10) and math.log10(1000). I have attached a patch that
forces math.log to internally use log10 when it gets the base 10. Patch
is against revision 66056. Also adds 3 tests to test_math.py to test new
behaviour implemented.