Fix print -> print()

Fix crash gpuadv inc1 broad y

Even on commented code. Just in case.
Also add __future__ imports.

Assert no CPU op for #2471

Change the elemwise input fusion limit to 32.

Fix nit spotted by @dwf

Fix warning reported on the mailing list

Respect PEP3113 (no more tuple unpacking arguments)

Replace except Class, e -> except Class as e