Partial revert of d5b66930

Tools like CRI-O or Red Hat's fork of Docker only need the OCI hook,
not the full runtime.

The hook is also likely to move at a different cadence than the full
runtime, which is tied to the upstream Docker releases.

Signed-off-by: NChristy Norman <christy@linux.vnet.ibm.com>
Signed-off-by: NFelix Abecassis <fabecassis@nvidia.com>

See https://github.com/opencontainers/runc/commit/db093f621f4e6d40feafbe6d7b89a9bee6f6ff85
We now let debuild detect and add the dependency for older versions of runc.

Signed-off-by: NChristy Norman <christy@linux.vnet.ibm.com>
Signed-off-by: NFelix Abecassis <fabecassis@nvidia.com>

Implement "-debug"

Any environment variable with the prefix "NVIDIA_REQUIRE_" will have
its value passed to nvidia-container-cli.

NVIDIA_CUDA_VERSION is no longer used and the CUDA images will be
replaced by a NVIDIA_REQUIRE_CUDA variable.

Those checks can be disabled globally in the configuration file or for
each container using NVIDIA_DISABLE_REQUIRE.

It gives the opportunity to perform cleanup in the main function.