Obsidian: Removed many grasses that *only* existed in Obsidian.

Tilesets should only change display, not functionality.
lint-raws.pl can now detect duplicate objects in tilesets and main objects.
Serious bugfix and clean-up of Obsidian plant_grasses.txt

* Removes duplicate grasses
* Changes biomes and tags of existing grasses to match masterwork version.
Merge branch 'master' into unified

* master:
  Serious bugfix and clean-up of Obsidian plant_grasses.txt
  lint-raws.pl can now detect duplicate objects in tilesets and main objects.
  Obsidian: Removed many grasses that *only* existed in Obsidian.

Conflicts:
	MasterworkDwarfFortress/graphics/Obsidian Soul/raw/objects/plant_grasses.txt