export-patches: Add a DFHack r4 nerfed_diseases export target

This will make thistleknot happy. ;)
Merge branch 'harmonize_raws'

* harmonize_raws:
  Ironhand: Remove pumpkins, sugar-cane, and turnips
  Adjust positioning of black-caps in ASCII/plant_standard.txt
  Manual harmonisation of plant raws across tilesets.
  show-tileset-diffs: Ignore DEAD_PICKED_TILE
  Manual harmonisation of many tilesets
  show-tileset-diffs: Ignore [BUILD_COLOR] tag
  Even more tileset harmonizations.
  show-tileset-diffs.pl - Tweaks and debugging
  More tileset harmonizations.
  show-tileset-diffs.pl - Less context on unified diffs.
  Automatic harmonization of graphics raws with master files.
Turn bogus [UNTOUCHED] tag into a comment.

For GH #41, all tilesets corrected.
Thanks to @splintermind for the spot.
Correct all GOLBINS to GOBLINS.

See GH #41. Thanks again to @splintermind for the spot.
Merge branch 'master' into unified

* master:
  Correct all GOLBINS to GOBLINS.
  Turn bogus [UNTOUCHED] tag into a comment.
  export-patches: Add a DFHack r4 nerfed_diseases export target