Change the mapping of the Dutch Almanacs reader

[tijmenbaarda]

• The information in bookseller should go to publisher/printer, but with bookseller as the role
• The location should go to holding
• The physical description should go to collation formula

In addition, Jeroen is busy changing the CSV file to expand the abbreviations and add some missing holding information. The code changes should wait for that.

[tijmenbaarda]

The second point, location to holding, has already been done.

[tijmenbaarda]

The first point is blocked by #50 ("Add role to publisher/printer field")

[tijmenbaarda]

The third point will be fixed by #99.