fix require in includes

sim/main.lua

@@ -19,6 +19,7 @@ print("Save location set to \""..OPT_SAVE_DIR.."\"")
 dofile("iosafe.lua")
 FFI = ffi
 Socket = socket
+Require = require
 dofile("utility.lua")
 dofile("simulation.lua")
 dofile("group.lua")
@@ -30,6 +31,7 @@ dofile("save.lua")
 dofile("network.lua")
 FFI = nil
 Socket = nil
+Require = nil
 
 -- Default settings
 OPT_TICK_ENABLED = true