C++ified some stuff.
Python: Doc strings and type checking
More work on python access to particle properties
Python: Better error messages when setting particle properties
Python: Made more ifdef-features available in python
python: Unit test for setting/getting basic particle properties
python: Allow integres as input when setting particle properties which are of type float
python: Particle data structure
More particle properties: rotation stuf, mass + unit test
Python: More particle properties. dipoles, director, virtual, vs_relative, charge + unit test
Merge branch 'master' of ssh://github.com/RudolfWeeber/espresso

Conflicts:
	src/particle_data.cpp
	src/particle_data.hpp
	src/python/code_info.pyx
	src/python/particle_data.pxd
	src/python/particle_data.pyx
	testsuite/python/particle.py