Fix/kvm disk image corruption
Tasks:
- 
merge disk-image-corruption present in instance-kvm.cfg.jinja2andinstance-kvm-import.cfg.jinja2.in - 
make it report information on failure  - 
assure it's being run in short time, by executing it with cron and sharing the status - it is short time, see:
 
 
du -sh srv/virtual.qcow2 ; time ./software_release/parts/qemu/bin/qemu-img check -U srv/virtual.qcow2
292G    srv/virtual.qcow2
No errors were found on the image.
4782342/4915200 = 97.30% allocated, 6.82% fragmented, 0.00% compressed clusters
Image end offset: 313466159104
real    0m0.801s
user    0m0.659s
sys     0m0.164s
- 
consider speed improvements - thus none needed