Added DruidSetup.java and install/druid_setup.sh to run it for Druid ensemble setup (put properties to zk, create zk zpaths, prep db, and dump properties/paths in zk); property druid.zk.paths.base can establish a namespace for a druid ensemble allowing more than one ensemble to use the same zookeepers; this namespace is the base zpath prefix for paths with properties in the form druid.zk.paths.*Path which are normally set automatically now; if druid.zk.paths.*Path are explicitly set, then all of them must be set with absolute paths to ensure careful attention; ZkSetup is now deprecated, use DruidSetup instead; examples/twitter RealtimeStandaloneMain will exit properly now after a kill -15 (control-c or kill pid) instead of hanging on an unstopped daemon.