DO NOT MERGE: Machinetalk preview - cython bindings to machinetalk (buildbot tickler PR)

this includes a first cut of the new HAL+RTAPI Python API, created with Python.

Some tests to get the idea are in nosetests/*.py 
The necessary strangeness to expose C API's lives in src/hal/cython/machinekit .

This is also a start at the nosetests regression test framework, which I hope can be used to replace the current 'runtests' script.