more virtual packages for providing libcuda.so.1 and libOpenCL.so.1

[Graham Inggs]

Hi Alberto

I know this is not part of the LP: #1129409 bug, but could you also add:

libGL 1 libgl1

to nvidia-graphics-drivers.shlibs.in please?

I'm going to make nvidia-cuda-toolkit build-depend on:
libcuda1 | nvidia-current | libcua-5.0-1

This should allow it to build on Debian and Ubuntu, but that means we 
can't drop the nvidia-current transitional package.
It should always depend on the minimum nvidia driver for that Ubuntu 
distribution.

Regards
Graham