Programs for batch-testing should have description in header comment

[falkecarlsen]

Due to the way parameterised tests work, only one element can be passed. In the case of batch testing, this needs to be the Cellmata source code.
Therefore, a good description of the functionality each program tests should be contained in the header comment for easy identification during testing.

This will also aid navigating and editing the files in all other cases.

@MathiasMehl may be a good candidate for fixing this issue.