Complex in Gpundarray on opencl

[nouiz]

We could use PyOpenCL w

http://documen.tician.de/pyopencl/array.html#complex-numbers

In addition, I've added a rudimentary facility for translating Fortran
kernels to OpenCL, see here:

https://github.com/inducer/pyopencl/tree/master/contrib/fortran-to-opencl