Forward port of the burnin migration
Forward port of the burnin migration

This is again a copy of the latest 1.2 burnin code related to migration.

Reviewed-by: ultrotter


dimara/ganeti,yiannist/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,bitemyapp/ganeti,leshchevds/ganeti,apyrgio/snf-ganeti,ganeti-github-testing/ganeti-test-1,mbakke/ganeti,ganeti/ganeti,ganeti/ganeti,onponomarev/ganeti,dimara/ganeti,grnet/snf-ganeti,andir/ganeti,ganeti/ganeti,yiannist/ganeti,leshchevds/ganeti,andir/ganeti,andir/ganeti,grnet/snf-ganeti,apyrgio/ganeti,apyrgio/snf-ganeti,bitemyapp/ganeti,mbakke/ganeti,onponomarev/ganeti,apyrgio/ganeti,mbakke/ganeti,leshchevds/ganeti