appear then disappear does not work as expected

[jaberg]

I have a slide defined like

`
slide(title='foo')
svg_include=(src='svg/foo.svg')
build appear(#label)
build disappear(#label)

`

and the result is a slide with the first frame of animation making label appear, and then the disappear has no effect. Either one works alone, it's just the sequence that causes a breakdown.

[jaberg]

The appear/disappear pattern works sometimes... I'll try to produce a testcase tomorrow or Friday.

[davidcox]

I've noticed problems here too, with svg elements. fade_in / fade_out seem to be much more reliable when dealing with SVGs.