Use "mod.conf" for dependencies and description (#2)

This patch makes moognu actually appear within the limits set by height_min and height_max.
We're now getting the upper and lower possible positions from the y_min and y_max variables calculated before.

By doing this, the frequency of spawned moognus will stay the same, while respecing the height limits.

depends.txt

@@ -1 +0,0 @@
-default

description.txt

@@ -1 +0,0 @@
-This mod adds a free alternative to the removed Nyan Cats: The MooGNU. 

init.lua

@@ -68,7 +68,7 @@ function moognu.generate(minp, maxp, seed)
 	for i = 1, max_num_moognus do
 		if pr:next(0, 1000) == 0 then
 			local x0 = pr:next(minp.x, maxp.x)
-			local y0 = pr:next(minp.y, maxp.y)
+			local y0 = pr:next(y_min, y_max)
 			local z0 = pr:next(minp.z, maxp.z)
 			local p0 = {x = x0, y = y0, z = z0}
 			moognu.place(p0, pr:next(0, 3), pr:next(3, 15))
@@ -84,4 +84,4 @@ end)
 minetest.register_alias("default:nyancat", "moognu:moognu")
 minetest.register_alias("nyancat:nyancat", "moognu:moognu")
 minetest.register_alias("default:nyancat_rainbow", "moognu:moognu_rainbow")
-minetest.register_alias("nyancat:nyancat_rainbow", "moognu:moognu_rainbow")
+minetest.register_alias("nyancat:nyancat_rainbow", "moognu:moognu_rainbow")

mod.conf

@@ -1 +1,3 @@
 name = moognu 
+depends = default
+description = This mod adds a free alternative to the removed Nyan Cats: The MooGNU.