cheats: Fix string formatting bug in cheat section.

Certain demo ROMs had unusual country codes, which weren't being
formatted properly in the cheat section header.  This would cause a
cascade of exceptions that would crash the app.  The bug can be repro-
duced using the CHROME.v64 demo rom available here:
http://mupen64.emulation64.com/down.htm
front: Change default gles2n64 frameskip to "no more than 5".