Hide Legacy Notifications Pane Toggle

[Vadoola]

In my limited testing so far of the beta I was very confused by the legacy notification pane toggle. Since at no point did I have any apps with legacy notifications I couldn't figure out what the toggle did, and had to ask in the G+ Community.

I think it might make more sense to hide this toggle if there are no legacy notifications. When a legacy notification appears the toggle does as well. This should retain functionality while minimizing the chance of confusion.

[cldx]

If you're brave you can test this from the devel branch....or wait for the next package where this should be gone.