Split recipe json

Splits the recipe.json file into small easier to browse files by
category.   No more 31000 line long recipe.json.
Tiniest PR ever - nix erroneous double space.
Fix some bad plural forms
Merge pull request #8056 from Wuzzy2/plurals

Fix some bad plural forms
Merge pull request #8055 from Rivet-the-Zombie/nix-double-space

Tiniest PR ever - nix erroneous double space.
Gives medical residents a stethoscope

Since they're in working-clothes already, the stethoscope seems
reasonable.  Forum topic at
http://smf.cataclysmdda.com/index.php?topic=6980.0
Special case recipes with no subcategory when filtering them instead of when loading them to break load order dependency.
Merge remote-tracking branch 'dda/pr/8027' into dda-master

* dda/pr/8027:
  Split recipe json

Conflicts:
	data/json/recipes/recipes.json
Restyle crafting.cpp and crafting.h.
Typo fix.
Merge pull request #8058 from KA101/MoreStethoscopes

Gives medical residents a stethoscope