1) imported glog to third_party (previous commit)
2) add support for third_party/update.sh to update just one pkg
3) search-and-replace:
s/log.Printf/glog.Infof/
s/log.Print/glog.Info/
s/log.Fatalf/glog.Fatalf/
s/log.Fatal/glog.Fatal/
4) convert glog.Info.*, err into glog.Error*
Adds some util interfaces to logging and calls them from each cmd, which
will set the default log output to write to glog. Pass glog-wrapped
Loggers to etcd for logging.
Log files will go to /tmp - we should probably follow this up with a
default log dir for each cmd.
The glog lib is sort of weak in that it only flushes every 30 seconds, so
we spin up our own flushing goroutine.
