SyntheticEvents have all their attributes to null for svg events

[vjeux]

@jonase reported this issue on IRC. It's broken both on 0.4.0 and master.

Repro: http://jsfiddle.net/vjeux/3X4Xb/
Click on the square
Expand the event, see that all the fields (including nativeEvent) are null

[vjeux]

Nevermind, it's a Chrome inspector bug. The values are actually there.

[zpao]

It's not actually a Chrome bug - since the event is pooled, the instance is actually cleaned up by the time you expand. That's why the initial rendering shows details (because it read them and wrote out right away) but the expansion doesn't. I got confused by this a while back before @yungsters explained it to me.

[vjeux]

Oh ... maybe we want to replace null by something more meaningful to the user. Like 'this is a pooled instance'