Add SHA256/512 module support.
Add basic support for C API attr members
GC: Attributes can have values that did not get allocated by the GC
Using the C API it's possible to create a Box instance without using our GC alloc.
For example have a look at md5module.c: PyDict_SetItemString(d, "MD5Type", (PyObject *)&MD5type);
Merge pull request #129 from undingen/sha_modules2

Add the sha256 and sha512 modules
Handle statically-allocated PyTypeObjects by having the collector keep a list of them.

Even with some optimizations it seems to hurt perf a little bit...
we'll have to see if it's worth it.

Also, rename "static roots" to "permanent roots", since it's
slightly different than the "static allocation" problem we're
tackling here.
Support for __get__ and __set__ for descriptors
Merge pull request #123 from tjhance/des

Conflicts:
	src/runtime/objmodel.cpp
Change 'expected: fail' to 'skip-if' since they work on some platforms and not others
Import some more CPython header files
Try to make the mailing lists more findable
fixed object.__new__ error message for >=2.7.4
Import some more CPython header files, and make some small Pyston tweaks to others
Add a number of C API functions

Working towards getting _sre.c to link (it compiles with the previous include/ additions)
Move some more stuff from capi.cpp to capi/

I guess our goal should be to eventually get rid of this directory -- this stuff
should mostly be just taken from CPython, and we could/should use their directory
names for that.  But for now it feels better than putting it all into a single file.
Add some more stubs
The _sre module now compiles and links (but doesn't run yet)
Enable init_sre and importing of the _sre module

fixed a number of small things to get it to work.

Also, updated most of the abort()-ing functions to print out a
Python-level stacktrace before actually calling abort() --
hopefully that won't cause any issues.
Merge pull request #130 from tjhance/fix_error_msg

fixed object.__new__ error message for >=2.7.4
Give up on implementing all of types.py for now
Some long support, trying to add tp_as_buffer
Implement the sequence iterator protocol

ie if you just have a __getitem__ method, you are still iterable.

This patch is unfortunately yet another performance regression, since
we obscure the behavior for known types (ie no longer try to go directly
to the __iter__).  Should make this into a call into type-specific behavior,
so that known types can use __iter__ if they have one?