File formats

[Tuomas Lukka <lukka@xxxxxxxxxxx>]

The save format will need to evolve - I've been talking with Ted and would
also like your comments on this.

The basic fundamentals are that

1) the current format grows too fast and too large

2) the users should have a clear model of what is what and control over
the storage

Ted suggests saving explicit version and keystroke (actually event, since
mouse is included) lists between them. However, these have their own
problems: 

- fragility: changing the meaning of a keystroke even slightly can totally
screw up the steps so that the interval between versions becomes
inaccessible.

- space: storing all the insignificant things as well (cursor moves, mouse
drags) may in fact use more space than the current system.

However, some change is necessary. I don't know what it should be yet.

	Tuomas