refactor python bindings for openann.
enum dispatcher are not needed. You only need to forward c-enums
integer values to the python interface (e.g. with constants in a class)
Merge branch 'master' of ssh://github.com/AlexanderFabisch/OpenANN into python

Conflicts:
	python/openann.pyx
add simple conversion for numby <-> eigen.
refactor old test example for the changed python interface.
fix indentation for optimize in StochasticGradientDescent.
Fix dependency management for python bindings.
python_extension_install target might not depending on python_extension,
that is added to the default targets.
Install python bindings to correct directory.
Merge branch 'Ruun-python'