This provides a fast way to check to see the data type of an ndarray.
For example, to check to see if an integer is 64 bits:

    PyArray_TYPE(a) == NPY_UINT64 or PyArray_TYPE(a) == NPY_INT64

--HG--
rename : Cython/Includes/python_string.pxd => Cython/Includes/python_bytes.pxd
rename : Cython/Includes/python_parse.pxd => Cython/Includes/python_getargs.pxd

fix bug 409: use cascaded assignments also for the complete rhs when optimising parallel assignments

detect optimisable IndexNodes assignments in ref-count optimisation, but do not activate them for now