Implemented lua script to verify recipes in JSON.
Added material checking to verifyer.
More fixes to the verifier script.
Avoid loading the same .json twice.
Make the lua binary configurable.
Renamed verifyjson to json-verify as per narc's suggestion.
Rename qualities to more sensible names.
Coughing 1
Fix missing paren
Further lower coughing sleep chance
Lower cough volume
Let traits with mixed effects appear in magenta font.

This adds a new element to the trait data structure: mixed_effect.
If this is true it is used to manually declare that some trait has both
positive and negative effects. This only affects the player UI.
Apply mixed_effect to mutations with mixed effects in mutations.json
Fixed bug in which "mixed_effect" color of traits reset to default color if "TRAITS" was selected in UI.

Also changed the mixed_effect color to pink.
Explain new mixed_effect in doc/JSON_INFO.md
Make threshold mutations appear in white font in player UI.
Added comment/lfs installation instructions for verifier script.
Improved debug output when trying to write an invalid value to an attribute in lua.
Print lua stack trace to debug log on error.
Change the lua/json load order.

main.lua is now loaded after JSON, but a new preload.lua can be loaded before JSON.