get cythonize script to work

I had to add a line

    # distutils : language = C++

near the top of c++ cython files
remove cython autogenerated c and cpp files
setup.py now uses cythonize.py automatically

forgot to add cythonize.py earlier
fix bug with setup.py dependencies
update .gitignore
Merge branch 'master' into cythonize

Conflicts:
	pele/optimize/_lbfgs_cpp.cpp
	pele/potentials/_lj_cpp.cpp
	pele/potentials/_morse_cpp.cpp
	pele/potentials/_pele.cpp
	pele/potentials/_pythonpotential.cpp
	run_cython.sh
use new cythonize method with fire and wca potentials
Merge pull request #19 from js850/cythonize

Cythonize files automatically in setup.py