Add a chat command to search items

Useful, for example, with /give, this adds a /search_items command which
returns all items where the name contains the given text. Although not
entirely consistent with the purpose of this mod, it makes use of the
same data already pre-cached for the crafting guide.

zcg/init.lua

@@ -98,6 +98,25 @@ zcg.load_all = function()
 	print("All crafts loaded !")
 end
 
+minetest.register_chatcommand("search_items", {
+    params = "<text>",
+    description = "search all craft items",
+    privs = {},
+    func = function(name, param)
+	if zcg.need_load_all then zcg.load_all() end
+        local found = false
+	for _, itemname in ipairs(zcg.itemlist) do
+            if itemname:find(param, 1, true) then
+                minetest.chat_send_player(name, itemname)
+                found = true
+            end
+        end
+        if not found then
+            minetest.chat_send_player(name, "No matching items.")
+        end
+    end
+})
+
 zcg.formspec = function(pn)
 	if zcg.need_load_all then zcg.load_all() end
 	page = zcg.users[pn].page