Adjusted smoke distribution function.
Fire adjustments.

- Reduced smoke by half.
- Flammable terrain no longer has to become an INFERNO just to convert the burning terrain to ashes.
- To grow past "small fire" stage, fire needs to be 1.) uncontained and 2.) either have a lot of fuel, or have nearby fires to help it grow
Ran map::process_fields_in_submap through astyle
Added 3-litre jar to the 3-litre jar of kompot recipe.
Correct the USE_METRIC_WEIGHTS option's usage, fixes #2394.
Similar fix regarding metric speeds.
adds wheat; wheat, blueberry, strawberry, weed seeds
adds bonemeal, flour, raw spaghetti, quern recipes
Gently encouraging seeds to spawn.
inventory::all_items_with_flag()
More seed spawning encouragement
Improves handling of sealed terrain
Adds plants; seeds; all that good stuff.

Also tweaks field plant yields.
new item flag: WATER_FRIENDLY
player::is_water_friendly()
New flag; WATERPROOF; slight WATER_FRIENDLY rejigger.
Reworks wetness morale.
correct seed weights
Swimming trunks
zap crbegin & friends