This reverts commit dab5ac36.

import the ``cython`` as module (no run  as a program)::

   >>> import cython

do the same than::

   >>> import Cython

But the same code was repeated in both places.

`load_entry_point()` is on Cython/__init__.py,
so::   %load_ext Cython is all you need to load the magic.

The canonical repository is avilable here:
https://github.com/ipython/ipython

cythonmagic.py is from 300ac3d
test_cythonmagic.py is from 0e0e6a8ed
ipython-COPYING.txt is a copy of COPYING.txt from 8a7c5eab
Cython Magics.ipynb is from

These files are the result of much work on the part of the IPython team, and
were available under the terms of the IPython license, also copied here as
ipython-COPYING.txt

utility code construction for struct conversion requires constructing the field conversion functions as well

--HG--
extra : amend_source : af016229b6c8c40168070e4d3a9581ed12500d3f

utility code construction for struct conversion requires constructing the field conversion functions as well

--HG--
extra : transplant_source : %A3%81%87%E2%0A%20%DA%7D%7E%5B%A0%9B%80i%F9%8Az%9B%F3%DC

Compute each Makefile variable immediately

Otherwise the variables get re-computed over and over again every time
they are used, slowing things up.  Especially if someone adapts the
Makefile to several targets in their own real project. :)

revert to using codecs.open() for output files instead of io.open() as the latter cannot write str objects in text mode under Py2 (and we erroneously do that in some spots)

make encoding detection code a bit faster if the first two source file lines are longer than 250 bytes