"Exceeded Maximum Dataset Limit (100)" in Running DaVinci on the grid

[chrisburr]

In the "Running DaVinci on the grid" lesson it currently submits a single job to process an entire bookkeeping path which results in the error "Exceeded Maximum Dataset Limit (100)".

We should instead limit the number of files processed until students have been taught about splitting.

Also:

• "will download most files below a size of XX MB" should have the XX replaced.