Include definitions

[magma1447]

Adds text files with the output of lvdisplay for each relevant block device.
Adds a dump of the qemu domain to the backup directory.

[magma1447]

Python isn't my language and I did not find a better way to get the lvdisplay output than to run the binary itself. I tried importing LVM bindings but failed already there. Then I didn't know how I would get the relevant data either. Like UUID and block device size for example.

I will keep the patch for myself if you do not like it, I would totally understand.