Remove beds/Changelog.txt & farming/API.txt

- beds/Changelog.txt probably won't be updated because http://dev.minetest.net/Changelog is used instead
- The information in farming/API.txt is already documented in game_api.txt

mods/beds/Changelog.txt

-1.0.1 beta
-----------
-- Add backwards compatibility with PilzAdam's beds mod
-- Fix placement
-- Fix small bugs
-- Prevent possible crash
-
-1.1
----
-- Add fancy bed model (based on jp's model)
-- Add API to register beds
-- Allow players always to detach from bed (by donat-b) 
-- If more than 50% of players want sleep they can skip the night
-- Don't show sleep dialog in singleplayer
-
-1.1.1
------
-- Prevent possbile crash by trying to reposition leaving players

mods/farming/API.txt

-farming.register_hoe(name, hoe definition)
- -> Register a new hoe, see [hoe definition]
- 
-farming.register_plant(name, Plant definition)
- -> Register a new growing plant, see [Plant definition]
-
-Hoe Definition
-{
-	description = "",	-- Description for tooltip
-	inventory_image = "unknown_item.png",	-- Image to be used as wield- and inventory image
-	max_uses = 30,	-- Uses until destroyed
-	material = "",	-- Material for recipes
-	recipe = {	-- Craft recipe, if material isn't used
-		{"air", "air", "air"},
-		{"", "group:stick"},
-		{"", "group:stick"},
-	}
-}
-
-Plant definition
-{
-	description = "",	-- Description of seed item
-	inventory_image = "unknown_item.png",	-- Image to be used as seed's wield- and inventory image
-	steps = 8,	-- How many steps the plant has to grow, until it can be harvested
-	^ Always provide a plant texture for each step, format: modname_plantname_i.png (i = stepnumber)
-	minlight = 13, -- Minimum light to grow
-	maxlight = default.LIGHT_MAX -- Maximum light to grow
-}
\ No newline at end of file