Add helper function to tell if a daemon is alive
Add helper function to tell if a daemon is alive

Add helper function 'utils.IsDaemonAlive' to tell if a daemon is alive
by name.  This function will be necessary for the KVM hypervisor to
determine if the KVM daemon is running and otherwise start it.

Signed-off-by: Jose A. Lopes <0fb9c4f8511df4ec2ae28af879e9d462f6218a2c@google.com>
Reviewed-by: Michele Tartara <05f7077a2c6cbbdc4af4ba42e3ef89a0df846179@google.com>

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