[Cython] heads-up on master branch status

[Stefan Behnel]

Hi,

by applying some initially small but perpetually growing fixes, I pushed
myself into a corner where the only escape was to rewrite BoolBinopNode
(short-circuiting and/or expressions). This was long overdue anyway and
simply wasn't done before because it's not trivial and quite risky. I think
I got it working better than before, but there are still corner cases that
require some further fighting. One of them currently crashes the pyregr
tests in Py2.7, it's this code:

    [tuple((e is None and 'X' or e) for e in t) for t in target]

Thank you, python-devs, for collecting these little gems in the test suite.
>From the C code this generates, the problem seems to be related to type
coercion in closures. I'm currently preparing my participation at
EuroPython next week, so I can't tell for sure when I'll be able to dig
into this. This means that current master may stay less stable than it
should be for a couple of more days.

Stefan