This allows to build an image with qcow2 as a disk backend.
The update implements a new class that inherits from QEMUVolume and just
needs the extention and file format.
Enables the use of Logical Volumes as disk backends.
It uses an existing volume group and has no support for creating a new one.
It will not override an existing logical volume and fail gracefully.
The lv is created, activated and then mounted as a loop device.
The boostraping process is then launched on the loop device.
Once the process is completed, the lv is unmounted and desactivated.
The created lv will be deleted should the boostraping process fail.
The lv must be activated before use.
A manifest has been included for testing purposes.
This is the first step in the effort of combining all documentation about
bootstrap-vz into sphinx while still being able to access it from github
(github can parse rst as well)
