Imports of serf command

PathSynopsis
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
github.com/hashicorp/serf/cmd/serf/command
github.com/hashicorp/serf/cmd/serf/command/agent
github.com/mitchellh/cli
io/ioutilPackage ioutil implements some I/O utility functions.
logPackage log implements a simple logging package.
osPackage os provides a platform-independent interface to operating system functionality.
os/signalPackage signal implements access to incoming signals.