Feature request: Add sys_set_ticks or sys_reset_ticks

[plattysoft]

While we can read the clock and wait for it, the TIME value is just an integer and eventually overflows, which leads to undesirable situations once the program has run for long enough.
It is much safer to reset the clock occasionally, for that we can have a sys_set_ticks or simply a sys_reset_ticks, which will be the equivalent to sys_set_ticks(0).

[retrodeluxe]

@plattysoft feel free to make pull requests to fix issues or add stuff you need.

[plattysoft]

I don't know enough assembly or the internals of the engine to be able to write that part, otherwise I would have gone for it straight away.