[Cython] new "cythonize" script

[Stefan Behnel]

Hi,

I added a script as "bin/cythonize" that acts as a frontend for the
cythonize() compilation tool (and distutils' build_ext).

https://github.com/cython/cython/blob/master/bin/cythonize

One cool feature is that you can use it to recursively compile packages:

    cythonize -i -k Cython

will translate, compile and link any .py files it finds in the Cython
package in-place (-i), ignoring anything that fails to compile (-k). If you
pass "--lenient", it ignores some compile time errors in favour of Python
compatibility. It also works on glob patterns etc.

I'm sure there's lots of features missing to make it nicely usable, so
please give it a try and speak up if you miss something. Improvements (in
the form of ideas and/or pull requests) are warmly appreciated.

Stefan