Animation update, for testing

![animate](https://cloud.githubusercontent.com/assets/6241382/2816499/fa3035ee-ceca-11e3-8ddd-e268026fd674.png)

So the start of a layout manager. I imagine be able to turn on or off bake, show for the whole layout.
__Also__ added persitant pre update handler.
There are issues with drawing more than one layout still in viewer draw.

It could be like this below but for this we need support in bakery, viewer draw, index viewer. A node can access the node group state like below
```
self.id_data.sv_show
self.id_data.sv_bake
self.id_data.sv_animate
```
![layoutmanager](https://cloud.githubusercontent.com/assets/6241382/2816567/f5009a90-cecb-11e3-9dfe-4f07af5235ce.png)