WIP: Homescreen grouping (v2)

Everything is in a group, dividers act as group separators.

Working (to a fashion):
- Rearranging groups
- Expanding/collapsing groups
- Creating new groups between groups
- Saving/restoring collapsed state
- Transitions

TODO:
- Editable group names
- General polish and optimisation (pending Gecko bugs)
This is starting to feel more ugly than it should. What are the cases where we need ```forceRender``` exactly?

I feel that we should either remove noTransform completely now, or maybe have it work better with forceRender. One thing might be to toggle the noTransform property instead, but this still feels wrong. Let me think about this some more.