add the command setkey, remove the command keycode, fix the IBM special characters handling in the grub shell, and fix a bug in print_error.

stage2/common.c

@@ -74,6 +74,7 @@ char *err_list[] =
   [ERR_UNRECOGNIZED] = "Unrecognized command",
   [ERR_WONT_FIT] = "Selected item cannot fit into memory",
   [ERR_WRITE] = "Disk write error",
+  [ERR_BAD_ARGUMENT] = "Invaild argument specified",
 };