Imports of gnatsd command

PathSynopsis
flagPackage flag implements command-line flag parsing.
github.com/nats-io/gnatsd/auth
github.com/nats-io/gnatsd/loggerPackage logger provides logging facilities for the NATS server
github.com/nats-io/gnatsd/serverPackage sublist is a routing mechanism to handle subject distribution and provides a facility to match subjects from published messages to interested subscribers.
osPackage os provides a platform-independent interface to operating system functionality.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.