Modpack refactor (#4)

Split this mod into a set of sub-mods in a modpack, and in the process did a whole bunch of renovations.

* updated Subterrane's API to allow for more patterned placement of things
* added "warrens"
* clean separation of flooded and non-flooded caverns
* rearranged biomes to make cavern layers more distinct
* added oil layer
* added underworld layer

df_farming/config.lua

@@ -0,0 +1,43 @@
+local CONFIG_FILE_PREFIX = "dfcaverns_"
+
+df_farming.config = {}
+
+local print_settingtypes = false
+
+local function setting(stype, name, default, description)
+	local value
+	if stype == "bool" then
+		value = minetest.setting_getbool(CONFIG_FILE_PREFIX..name)
+	elseif stype == "string" then
+		value = minetest.setting_get(CONFIG_FILE_PREFIX..name)
+	elseif stype == "int" or stype == "float" then
+		value = tonumber(minetest.setting_get(CONFIG_FILE_PREFIX..name))
+	end
+	if value == nil then
+		value = default
+	end
+	df_farming.config[name] = value
+	
+	if print_settingtypes then
+		minetest.debug(CONFIG_FILE_PREFIX..name.." ("..description..") "..stype.." "..tostring(default))
+	end	
+end
+
+local plants = {
+	{name="cave_wheat", delay_multiplier=1},
+	{name="dimple_cup", delay_multiplier=3},
+	{name="pig_tail", delay_multiplier=1},
+	{name="plump_helmet", delay_multiplier=3},
+	{name="quarry_bush", delay_multiplier=2},
+	{name="sweet_pod", delay_multiplier=2},
+}
+
+--Plants
+
+setting("int", "plant_growth_time", 500, "Base plant growth time")
+
+for _, plant in pairs(plants) do
+	setting("float", plant.name.."_delay_multiplier", plant.delay_multiplier, plant.name.." growth delay multiplier")
+end
+
+setting("bool", "light_kills_fungus", true, "Light kills fungus")