[packstack] fix value of CONFIG_CINDER_NFS_MOUNTS
[packstack] make NTP servers configurable
[packstack] beautified configuration file
[packstack] remove existing logfiles before starting the bootstrap
[packstack] do not handle NTP addresses as a node
[packstack] rename compute nodes to compute
[packstack] reuse provision code in Vagrantfile
[packstack] node --> compute
[packstack] rename node filer to nfs