Change the way we decide that a node is up and ready for use. Instead
of just pinging it, poll its eventstate in the database, and wait until it's reported ISUP. This way, we don't report that a node is ready before it really is. Also bumped up the timeout by a couple of minutes to account for the extra time it takes for the OS to boot. Right now, if the OS is considered pingable, we assume that it will report ISUP. In the future, however, when the node state is more formalized, we will have better ways of determining this.