Added inv_food function to display only food items.

Plus some groundwork for easier reloading of gasoline guns and tools.

Conflicts:

	README.md
	item.cpp
Inventory screen shows only suitable items for certain commands (eat, read, wear, take off)
Fixed crafting recipes consuming all gasoline, readjusted gasoline requirements in recipes.

Recipes that require containers now check that containers are empty

Conflicts:

	crafting.cpp