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
Merge branch 'aggies-unite'
Merge branch 'swimming-pool-episode-two'