Updated the checkpointing tutorial.

The checkpointing tutorial should now be compatible with CellBlender
0.1.57.

A note about version numbers was also added.
Updated the release pattern tutorial.

The release pattern tutorial should now be compatible with CellBlender
0.1.57.

A note about version numbers was also added.
Added/updated version information.

The tutorials now say what version of CellBlender and Blender were used
to create them. The git SHA1 ID is also in the comments of the rst
files.