Add GpuArray_IS_C_CONTIGUOUS and GpuArray_IS_F_CONTIGUOUS and fix GpuArr...

...ay_ISFORTRAN.

The last one should be true only if fortran and not c order:

http://docs.scipy.org/doc/numpy/reference/c-api.array.html#PyArray_ISFORTRAN
I see in the C code that it returns 0 by default, but it's probably a good idea.