proposal for Ttime, etc. in MiNT

[Tamminen Eero <t150315@proffa.cc.tut.fi>]

> Have a look at the code and tell me better ways to implement the UTC based
> time functions in MiNT. (It seems to work here on my machine.)
...
> /* If anyone tells me how I could use some NON-fractional timer < 5ms
>	(from Timer A which is unused I think) I'll do it, instead of
>	5ms ticks. 
...

IMHO 5ms is quite sufficiant.  There're not many user programs which
would need greater accuracy.  Screen is updated only at 13-20ms
intervals, so even for animations and (most) games this should be
enough.

I'd like myself to know how scheduler-friendly the Vsunc() call (used on
games which have non-flickering screen output) is?

	- Eero