Big refactoring of libvirtio

use of the same structs with small differences on host and guest side.

VirtIO: Adapted the device initialization process to make it work.

- Changes in the notification protocol between host and guest
- Addition of information to serve the device intitalization (host side)
- introduced a yield when waiting for the ready bit.
- device specific setup is now handled during device_open

VirtIO:

extended library to distinguish between host and guest
added flounder / xeon phi channels for opening devices etc

Block Driver
Parts of an initiali implementation
Device initialization

VirtIO

- Addition of block device specific files in the VirtIO Library
- Changes to the block devices Mackerel specification
- Implementation of dequeue / enqueue of Virtqueues