(35% faster according to pybench)

convert test_locale to unittest, and add a mechanism to override localconv() results for further testing (#1864, #1222)

This patch publishes the work done until now
for Python 3.0 compatibility. Still a lot
to be done.

When possible, we use 3.0 features in Python 2.6,
easing development and testing, and exposing internal
changes to a wider audience, for better test coverage.

Some mode details:
http://www.jcea.es/programacion/pybsddb.htm#bsddb3-4.7.2

was not always being done properly in some python types and extension
modules.  PyMem_MALLOC, PyMem_REALLOC, PyMem_NEW and PyMem_RESIZE have
all been updated to perform better checks and places in the code that
would previously leak memory on the error path when such an allocation
failed have been fixed.

The problem was introduced by r53954, the correction is to restore the symmetry between
PyFrame_FastToLocals and PyFrame_LocalsToFast

(I thought there was a script to automate this kind of updates)

Since python doesn't provide any particular random data, it seems more reasonable anyway.