Detailed explanation of these changesets and why they are so big:

The Nieuwlandsreid Saltmarsh area of Ameland was a mess, mapping wise. It consisted of 3 huge overlapping MP's, with 29, 46 and 25 members respectively. The 2 Saltmarsh MP's caused all inner areas that were part of the other MP to appear as if they were covered by wetland. Instead of having to figure out how to untangle that mess I decided to instead delete them and make a single MP from scratch, as that seemed like the better solution to me. 

- Removed mess that involved 3 large overlapping MP's that were causing problems and remade a single MP from scratch
- removed about a hundred random incorrect meadow areas, a bunch of incorrect heathland and other incorrect details
- redid tidal creeks and improved details
- updated the very out-of-date terrain
- various other small improvements

Will also be doing some further improvements later on, as detail is still lacking in some parts. I'll keep those changesets reasonably sized.