WIP: Side drawer UI update

Fixes issues #798 and #1053.

This PR moves the flight mode panel from the side drawer window to a sliding up window similar to the one in Google Maps.
On tablet, this results in the side drawer window being removed from the UI. On phone, the side drawer window is still there, but now it only contains the telemetry widget.

The new sliding up window gives more real estate than the side drawer window. This is illustrated by an update to the `guided` and `follow-me` mode window below.

**Note**: In the phone screenshots, the telemetry is shown opened, but since it's withing the side drawer window, it can be closed as well just like it's now.

Tablet:
=====
![tablet_port_collapsed](https://cloud.githubusercontent.com/assets/914968/4512074/371e4c32-4b3c-11e4-86ee-274c2482a0a4.png)

![tablet_port_expanded_3](https://cloud.githubusercontent.com/assets/914968/4512085/48cdccc8-4b3c-11e4-9a5f-530a0761da55.png)

![tablet_port_expanded_1](https://cloud.githubusercontent.com/assets/914968/4512093/5add323c-4b3c-11e4-975f-483036b0e2b3.png)

![tablet_land_expanded_3](https://cloud.githubusercontent.com/assets/914968/4512135/cff00496-4b3c-11e4-8181-9550e18fa255.png)


Phone:
======
![phone_port_collapsed](https://cloud.githubusercontent.com/assets/914968/4512139/dcf987e8-4b3c-11e4-9446-72247b7dfd33.png)

![phone_port_expanded_3](https://cloud.githubusercontent.com/assets/914968/4512141/e5c02652-4b3c-11e4-87fd-ed5367e52570.png)

![phone_port_expanded_2](https://cloud.githubusercontent.com/assets/914968/4512144/eed23b04-4b3c-11e4-9eb5-e477152fc5d0.png)

![phone_land_collapsed](https://cloud.githubusercontent.com/assets/914968/4512148/fa23c3d8-4b3c-11e4-841d-d2471d958774.png)

![phone_land_expanded_2](https://cloud.githubusercontent.com/assets/914968/4512152/05811604-4b3d-11e4-904d-a175463ebccf.png)