hal/python: Cython bindings for HAL by Pavel Shramov

see http://psha.org.ru/cgit/psha/emc2.git/commit/?h=wip-cython&id=7137c5f8874948541de1aa796c9e8c1b2f8f7fb8

my autoconf integration is naive and needs work - this should not depend on cython
and it should retrigger cython only if a pxy/pyx file changed
A regression test would be great.

This is intended as a starting point for work on issue https://github.com/machinekit/machinekit/issues/143 .

To extend this work, you need cython installed:

  sudo apt-get install cython

Signed-off-by: Michael Haberler <git@mah.priv.at>