Better "cheat" warning and some improvements

Cheat: the warning is shown for 3 seconds, after the cheat is disabled.
It helps the user to see if he used some cheat without purpose.

Drawing text: improved the performance, by avoinding the creation of
tables and direct use of string.format, named "fmt" here.

Input display: fixed a bug that desynced the frame vs input each time
the user reloaded the script without reseting the lua virtual machine.