[Grace-core] Animations in Grace

[Marco Servetto]

> I taught a few young people to program things in Squeak's EToys, which
> uses the stepping model. Here are a few notes from that.
> A really important primitive that Alan Kay insisted is easy to access
> is "repeat on every tick". Does Grace have such a thing? In EToys,
Hi Lex, can you expand on this point?
I'm thinking on how to make GUI in a decent way lately too.