[WIP][ROM][6.0] Nexus 7 Marshmallow - Android 6.0

It was bound to happen, so here it is. The Grouper running Android 6.0!

What works:
- display
- audio
- Bluetooth (partially)
- Multiwindow
- Auto-rotate

What's broken:
- OTG
- surfaceflinger*

What's untested:
- camera
- NFC

I will not offer a ROM zip at this point due to the fact that the rootfs is inherently insecure for the time being. However, the sources are available below and should be bootable.




Sources:
http://github.com/Grouper-marshmallow

CREDITS:
@dolorespark - ramdisk fixes
@Ziyann - kernel work and device tree