fix: list MAME's hash, plugins and floppy sounds

The libretro core passes system/mame/{hash,plugins,samples} (retro_init.cpp:111-155). Software lists are required in mamemess, where softlists are on by default. The trees and the 19 floppy samples are collected from libretro/mame at the pin.

bios/Other/mame/plugins/data/init.lua

@@ -0,0 +1,91 @@
+-- license:BSD-3-Clause
+-- copyright-holders:Carl
+-- A data script should contain two functions check which takes a set name and returns the data
+-- heading if it supports the set otherwise nil and get which returns the data
+-- the script should be named data_<name>.lua
+-- this is set default on in the plugin.json
+local exports = {
+	name = 'data',
+	version = '0.0.2',
+	description = 'Data plugin',
+	license = 'BSD-3-Clause',
+	author = { name = 'Carl' } }
+
+local data = exports
+
+local plugindir
+
+local reset_subscription
+
+function data.set_folder(path)
+	plugindir = path
+end
+
+function data.startplugin()
+	local data_scr = {}
+	local valid_lst = {}
+	local cur_set
+	local cur_list
+
+	reset_subscription = emu.add_machine_reset_notifier(
+			function ()
+				data_scr = {}
+				for file in lfs.dir(plugindir) do
+					local name = string.match(file, '^(data_.*).lua$')
+					if name then
+						local script = require('data/' .. name)
+						if script then
+							table.insert(data_scr, script)
+						end
+					end
+				end
+			end)
+
+	emu.register_callback(
+			function (set)
+				local ret = {}
+				if set == '' then
+					set = emu.romname()
+				end
+				if set == cur_set then
+					return cur_list
+				end
+				cur_set = set
+				if not set then
+					return nil
+				end
+				valid_lst = {}
+				for num, scr in ipairs(data_scr) do
+					local setname, softname = set:match('^([^,]+),?(.*)$')
+					if softname == '' then
+						softname = nil
+					end
+					local name = scr.check(setname, softname)
+					if name then
+						table.insert(ret, name)
+						table.insert(valid_lst, scr)
+					end
+				end
+				cur_list = ret
+				return ret
+			end,
+			'data_list')
+
+	emu.register_callback(
+			function (num)
+				return valid_lst[num + 1].get()
+			end,
+			'data')
+
+	emu.register_callback(
+			function (num)
+				local ver
+				if valid_lst[num + 1].ver then
+					ver = valid_lst[num + 1].ver()
+				end
+				return ver or ''
+			end,
+			'data_version')
+end
+
+return exports