Root of the issue goes to the fact that since the very beginning Cycles was
using ZYX euler rotation for mapping shader node but blender was always
using XYZ euler rotation.

This commit switches Cycles to use XYZ euler order and adds versioning code
to preserve backward compatibility.

There was no really nice solution here because either we're ending up with
versioning code or we'll need to deal with all sort of exceptions from blender
side in order to support ZYX order for the mapping node. The latest one is
also creepy from the other render engines points of view -- that might break
compatibility with existing bindings or introduce some extra headache for them
in the future.

This could also become a PITA for us with need of supporting all sort of weird
and wonderful exceptions in the refactored viewport project.