MR include files for Maya 6 and above
Since version 6 Maya requires unique node IDs for custom Mental Ray
shaders and can handle only one shader without such an ID. (The ID is
just an extra line of information found in the include file of the shader.)
The reason of this is very simple, Maya uses such node IDs for every maya
node to store the node information in the maya binary format. Therefore
IDs are not required for the maya ascii format, that allows converting
from one node id to the other by saving to ascii format.
Simply overwrite the old files found in the `maya/mentalray/include` directory.