[Evolution-hackers] filter refactor, rule parts

[Dan Winship]

> The main difference here is that any changes to the filter types would
> require a change to the code.

That doesn't seem like a huge problem.

> On the other hand, it would make it
> easier to write coded plugins to implement new types

Yes, although they'd have to be backend-specific. But there's no getting
around that I guess.

> Any thoughts?  Would it make exchange server-side easier?

I don't know. I don't think we'd ever figured out how we were going to
do the GUI, so there's nothing to compare it to. But this way sounds
fine.

-- Dan