Add a ReturnConvention for getattrs that can C++ throw

Otherwise callers have no way of knowing if an exception might
occur in the rewritten code, and they'd have to conservatively
not rewrite those cases (such as 3-arg getattr).

Well, previously getattr() wasn't doing that, so it would rewrite
itself correctly for a descriptor that is not throwing now, but would
start throwing later (those exceptions would get propagated instead
of being caught by getattr).

Directly use cpythons errors.c file

switch to cpython traceback implementation

The performance is the same but it removes quite a lot of unnecessary code and makes hopefully maintaining our codebase a little easier.

Get libsass working by fixing c++ EH handling

socket fixes

add the _locale and cPickle modules

the module is much faster than the python implementation
But I had to change the code a little bit because of our GC and more importantly because some of our types have different names etc...
I also noticed that we failed to to set capifunc.__module__ in a lot of cases which made pickle error

The static variables should be fine because this is compiled as shared object which we the GC will automatically scan.

Make the pycrypto integration test run the testsuite

fix misc problems (del nonexisting attr, bool ops, super: support nonexisting attr,...)

The socket implementation used to only call close on a socket when all references where gone.
This works fine for cpython which uses reference counting but for pyston (and pypy) this is a problem.
This works around the problem in a similar way as pypy does.
It also uses the same method names so that 3th party libs which already support pypy will automatically work with pyston too.
(e.g. urllib3)

Enable working cpython tests

Switch to cpythons file object implementation

fixes test_file2k, test_file_eintr and test_softspace

fix misc minor compatibility issues

and switch to the correct urllib test version

this increases the compatibility if some one is using 'is' identity comparisons
instead of equality '==' comparisons.

Mention automake in the dependencies

Add signal support