makes lighting fires during sunny days via lens possible
also adds magnifying glasses to the game
fix for mag glass
flag added to be able to use the lens_fire items without drawing charges
should fix most of the merge errors/misclicks
small description typo fix
Load specials if present
Transform to new format
Experimental batch crafting time reduction
Gourmand check

Should fix #6985, but then I thought I nailed it already.
fixed recipes file
camp fire + lens fire are long term actions
pending: unified firestarter function
Fix monsters.json formatting
Fix style regression in monstergenerator.cpp
Handle monsters with no specials properly
Clean JSON for monsters with no specials
unifies firestart functions from different tools.
fixes some calculation errors when lighting a fire.
also stops lighting a fire with a lens if the weather changes.
todo: recalculate time to start a fire with a lens if weather changes
Remove redundant get_batch_time function
Remove redundant instances of difficulty property

Difficulty is now loaded only by the requirements class, and is
automatically shared with constructions and recipes.
typo and clarity fixes
constant checking of weather changes + updating of turns_left accordingly is
done
Logistic function batch crafting time reduction

A recipe can now have optional `batch_time_factors` array which
specifies maximum time reduction for a single craft as a percentage,
and a minimum batch size to reach the full time reduction.