Updated the rat nmj and lotka-volterra tutorials.

The rat nmj and lotka-volterra tutorial should now be compatible with
CellBlender 1.0 RC. This mainly entailed updating the blend files, but
we might want to add more detailed descriptions of the models at some
point in the future.
Added warning for tutorials not yet updated.

Some tutorials have a warning now to indicate that they have not yet
been updated for CellBlender 1.0 RC.