Add option to burnin only a given set of nodes
Add option to burnin only a given set of nodes

This patch adds a '-n' option to burnin that takes a comma-separated
list of nodes to perform the burnin on.

Reviewed-by: ultrotter


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