Enable more of the IO library in Lua sandbox

Also changes the Lua warning color to red.

aiserver.py

@@ -1018,7 +1018,7 @@ def lua_warn(msg):
     if(vars.lua_logname != vars.lua_koboldbridge.logging_name):
         vars.lua_logname = vars.lua_koboldbridge.logging_name
         print(colors.BLUE + lua_log_format_name(vars.lua_logname) + ":" + colors.END, file=sys.stderr)
-    print(colors.YELLOW + msg.replace("\033", "") + colors.END)
+    print(colors.RED + msg.replace("\033", "") + colors.END)
 
 #==================================================================#
 #  Decode tokens into a string using current tokenizer

bridge.lua

@@ -1509,6 +1509,11 @@ return function(_python, _bridged)
             ult = math.ult,
         },
         io = {
+            stdin = io.stdin,
+            stdout = io.stdout,
+            stderr = io.stderr,
+            input = io.input,
+            output = io.output,
             read = io.read,
             write = io.write,
             flush = io.flush,