Bug#785569: Work in progress in personal GitHub fork

[Ghislain Vaillant <ghisvail@gmail.com>]

Progress of the packaging can be checked out at:
https://github.com/ghisvail/arrayfire/tree/debian

So far, the CPU backend builds fine and the packaging is lintian-free.
Testing required. I will then transfer the work to its Debian Science
repository.

The OpenCL backend requires additional dependencies (clBLAS, clFFT)
which are missing in Debian.

The CUDA backend should be more straightforward. Also, I am not sure
whether it is more desirable to build the CUDA backend and have
ArrayFire in contrib or stick with just CPU and OpenCL and have it in
main.

Cheers,
Ghislain