Change hoe_on_use to farming.hoe_on_use, for use and override by mods.

mods/farming/init.lua

 -- Minetest 0.4 mod: farming
 -- See README.txt for licensing and other information.
 
+farming = {}
+
 --
 -- Soil
 --
@@ -62,7 +64,7 @@ minetest.register_abm({
 -- Hoes
 --
 -- turns nodes with group soil=1 into soil
-local function hoe_on_use(itemstack, user, pointed_thing, uses)
+function farming.hoe_on_use(itemstack, user, pointed_thing, uses)
 	local pt = pointed_thing
 	-- check if pointing at a node
 	if not pt then
@@ -109,7 +111,7 @@ minetest.register_tool("farming:hoe_wood", {
 	inventory_image = "farming_tool_woodhoe.png",
 	
 	on_use = function(itemstack, user, pointed_thing)
-		return hoe_on_use(itemstack, user, pointed_thing, 30)
+		return farming.hoe_on_use(itemstack, user, pointed_thing, 30)
 	end,
 })
 
@@ -118,7 +120,7 @@ minetest.register_tool("farming:hoe_stone", {
 	inventory_image = "farming_tool_stonehoe.png",
 	
 	on_use = function(itemstack, user, pointed_thing)
-		return hoe_on_use(itemstack, user, pointed_thing, 90)
+		return farming.hoe_on_use(itemstack, user, pointed_thing, 90)
 	end,
 })
 
@@ -127,7 +129,7 @@ minetest.register_tool("farming:hoe_steel", {
 	inventory_image = "farming_tool_steelhoe.png",
 	
 	on_use = function(itemstack, user, pointed_thing)
-		return hoe_on_use(itemstack, user, pointed_thing, 200)
+		return farming.hoe_on_use(itemstack, user, pointed_thing, 200)
 	end,
 })
 
@@ -136,7 +138,7 @@ minetest.register_tool("farming:hoe_bronze", {
 	inventory_image = "farming_tool_bronzehoe.png",
 	
 	on_use = function(itemstack, user, pointed_thing)
-		return hoe_on_use(itemstack, user, pointed_thing, 220)
+		return farming.hoe_on_use(itemstack, user, pointed_thing, 220)
 	end,
 })